1
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Huo X, Xie Y, Wang X, Zhang L, Yang M. Reduction reactions at the interface between CdS quantum dot and Z-type ligands driven by electron injection in the electroluminescent processes. J Chem Phys 2024; 161:024304. [PMID: 38984958 DOI: 10.1063/5.0196243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 06/24/2024] [Indexed: 07/11/2024] Open
Abstract
The efficient and stable electroluminescence of quantum dots (QDs) is of great importance in their applications in new display technologies. The short service life of blue QDs, however, hinders their development and commercialization. Different mechanisms have been proposed for the destabilization of QDs in electroluminescent processes. Based on real-time time-dependent density functional theory studies on the QD models covered by Z-type ligands (XAc2, X = Cd, Zn, Mg), the structural evolution is simulated to reveal the mechanism of the reduction reactions induced by electron injection. Our simulations reproduce the experimental observations that the reduction reactions occur at the QD-ligand interface, and the reduced Cd atom is almost in a zero valence state. However, different sites are predicted for the reactions in which the surface metal atom of the QD instead of the metal atom in the ligands is reduced. As a result, one of the arms of the chelate ligand leaves the QD, which tends to cause damage to its electroluminescent performance. Our findings contribute to a mechanistic understanding of the reduction reactions that occurred at the QD-ligand interface.
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Affiliation(s)
- Xiangyu Huo
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Yujuan Xie
- School of Science, Westlake University, Hangzhou 310030, China
| | - Xian Wang
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, Singapore 637371
| | - Li Zhang
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - Mingli Yang
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
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2
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Li Q, Wu K, Zhu H, Yang Y, He S, Lian T. Charge Transfer from Quantum-Confined 0D, 1D, and 2D Nanocrystals. Chem Rev 2024; 124:5695-5763. [PMID: 38629390 PMCID: PMC11082908 DOI: 10.1021/acs.chemrev.3c00742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 03/29/2024] [Accepted: 04/02/2024] [Indexed: 05/09/2024]
Abstract
The properties of colloidal quantum-confined semiconductor nanocrystals (NCs), including zero-dimensional (0D) quantum dots, 1D nanorods, 2D nanoplatelets, and their heterostructures, can be tuned through their size, dimensionality, and material composition. In their photovoltaic and photocatalytic applications, a key step is to generate spatially separated and long-lived electrons and holes by interfacial charge transfer. These charge transfer properties have been extensively studied recently, which is the subject of this Review. The Review starts with a summary of the electronic structure and optical properties of 0D-2D nanocrystals, followed by the advances in wave function engineering, a novel way to control the spatial distribution of electrons and holes, through their size, dimension, and composition. It discusses the dependence of NC charge transfer on various parameters and the development of the Auger-assisted charge transfer model. Recent advances in understanding multiple exciton generation, decay, and dissociation are also discussed, with an emphasis on multiple carrier transfer. Finally, the applications of nanocrystal-based systems for photocatalysis are reviewed, focusing on the photodriven charge separation and recombination processes that dictate the function and performance of these materials. The Review ends with a summary and outlook of key remaining challenges and promising future directions in the field.
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Affiliation(s)
- Qiuyang Li
- Department
of Physics, University of Michigan, 450 Church St, Ann Arbor, Michigan 48109, United States
| | - Kaifeng Wu
- State
Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation
Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
| | - Haiming Zhu
- Department
of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Ye Yang
- The
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM
(Collaborative Innovation Center of Chemistry for Energy Materials),
College of Chemistry & Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, China
| | - Sheng He
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Tianquan Lian
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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3
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Di Giacomo A, Myslovska A, De Roo V, Goeman J, Martins JC, Moreels I. Selenium reduction pathways in the colloidal synthesis of CdSe nanoplatelets. NANOSCALE 2024; 16:6268-6277. [PMID: 38450545 PMCID: PMC10956962 DOI: 10.1039/d3nr05157a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 02/21/2024] [Indexed: 03/08/2024]
Abstract
Several established procedures are now available to prepare zinc blende CdSe nanoplatelets. While these protocols allow for detailed control over both thickness and lateral dimensions, the chemistry behind their formation is yet to be unraveled. In this work, we discuss the influence of the solvent on the synthesis of nanoplatelets. We confirmed that the presence of double bonds, as is the case for 1-octadecene, plays a key role in the evolution of nanoplatelets, through the isomerization of the alkene, as confirmed by nuclear magnetic resonance spectroscopy and mass spectrometry. Consequently, 1-octadecene can be replaced as a solvent (or solvent mixture), however, only by one that also contains α protons to CC double bonds. We confirm this via synthesis of nanoplatelets in hexadecane spiked with a small amount of 1-octadecene, and in the aromatic solvent 1,2,3,4-tetrahydronaphthalene (tetralin). At the same time, the chemical reaction leading to the formation of nanoplatelets occurs to some extent in saturated solvents. A closer examination revealed that an alternative formation pathway is possible, through interaction of carboxylic acids, such as octanoic acid, with selenium. Next to shedding more light on the synthesis of CdSe nanoplatelets, fundamental understanding of the precursor chemistry paves the way to use optimized solvent admixtures as an additional handle to control the nanoplatelet synthesis, as well as to reduce potential self-polymerization hurdles observed with 1-octadecene.
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Affiliation(s)
| | - Alina Myslovska
- Department of Chemistry, Ghent University, 9000-Gent, Belgium.
| | - Vic De Roo
- Department of Organic and Macromolecular Chemistry, Ghent University, 9000-Gent, Belgium
| | - Jan Goeman
- Department of Organic and Macromolecular Chemistry, Ghent University, 9000-Gent, Belgium
| | - José C Martins
- Department of Organic and Macromolecular Chemistry, Ghent University, 9000-Gent, Belgium
| | - Iwan Moreels
- Department of Chemistry, Ghent University, 9000-Gent, Belgium.
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4
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Monego D, Dutta S, Grossman D, Krapez M, Bauer P, Hubley A, Margueritat J, Mahler B, Widmer-Cooper A, Abécassis B. Ligand-induced incompatible curvatures control ultrathin nanoplatelet polymorphism and chirality. Proc Natl Acad Sci U S A 2024; 121:e2316299121. [PMID: 38381786 PMCID: PMC10907275 DOI: 10.1073/pnas.2316299121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/22/2023] [Indexed: 02/23/2024] Open
Abstract
The ability of thin materials to shape-shift is a common occurrence that leads to dynamic pattern formation and function in natural and man-made structures. However, harnessing this concept to rationally design inorganic structures at the nanoscale has remained far from reach due to a lack of fundamental understanding of the essential physical components. Here, we show that the interaction between organic ligands and the nanocrystal surface is responsible for the full range of chiral shapes seen in colloidal nanoplatelets. The adsorption of ligands results in incompatible curvatures on the top and bottom surfaces of the NPL, causing them to deform into helicoïds, helical ribbons, or tubes depending on the lateral dimensions and crystallographic orientation of the NPL. We demonstrate that nanoplatelets belong to the broad class of geometrically frustrated assemblies and exhibit one of their hallmark features: a transition between helicoïds and helical ribbons at a critical width. The effective curvature [Formula: see text] is the single aggregate parameter that encodes the details of the ligand/surface interaction, determining the nanoplatelets' geometry for a given width and crystallographic orientation. The conceptual framework described here will aid the rational design of dynamic, chiral nanostructures with high fundamental and practical relevance.
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Affiliation(s)
- Debora Monego
- School of Chemistry, Australian Research Council (ARC) Centre of Excellence in Exciton Science, University of Sydney, Sydney, NSW2006, Australia
- The University of Sydney Nano Institute, University of Sydney, Sydney, NSW2006, Australia
| | - Sarit Dutta
- ENSL, CNRS, Laboratoire de Chimie, UMR 5182, 46 allée d’Italie, LyonF-69364, France
| | - Doron Grossman
- Laboratoire d’hydrodynamique (LadHyX), UMR, École Polytechnique, CNRS, PalaiseauF-91128, France
| | - Marion Krapez
- School of Chemistry, Australian Research Council (ARC) Centre of Excellence in Exciton Science, University of Sydney, Sydney, NSW2006, Australia
- The University of Sydney Nano Institute, University of Sydney, Sydney, NSW2006, Australia
| | - Pierre Bauer
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, VilleurbanneF-69622, France
| | - Austin Hubley
- ENSL, CNRS, Laboratoire de Chimie, UMR 5182, 46 allée d’Italie, LyonF-69364, France
| | - Jérémie Margueritat
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, VilleurbanneF-69622, France
| | - Benoit Mahler
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, VilleurbanneF-69622, France
| | - Asaph Widmer-Cooper
- School of Chemistry, Australian Research Council (ARC) Centre of Excellence in Exciton Science, University of Sydney, Sydney, NSW2006, Australia
- The University of Sydney Nano Institute, University of Sydney, Sydney, NSW2006, Australia
| | - Benjamin Abécassis
- ENSL, CNRS, Laboratoire de Chimie, UMR 5182, 46 allée d’Italie, LyonF-69364, France
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5
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Lee HC, Bootharaju MS, Lee K, Chang H, Kim SY, Ahn E, Li S, Kim BH, Ahn H, Hyeon T, Yang J. Revealing Two Distinct Formation Pathways of 2D Wurtzite-CdSe Nanocrystals Using In Situ X-Ray Scattering. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2307600. [PMID: 38072639 PMCID: PMC10853705 DOI: 10.1002/advs.202307600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/21/2023] [Indexed: 02/10/2024]
Abstract
Understanding the mechanism underlying the formation of quantum-sized semiconductor nanocrystals is crucial for controlling their synthesis for a wide array of applications. However, most studies of 2D CdSe nanocrystals have relied predominantly on ex situ analyses, obscuring key intermediate stages and raising fundamental questions regarding their lateral shapes. Herein, the formation pathways of two distinct quantum-sized 2D wurtzite-CdSe nanocrystals - nanoribbons and nanosheets - by employing a comprehensive approach, combining in situ small-angle X-ray scattering techniques with various ex situ characterization methods is studied. Although both nanostructures share the same thickness of ≈1.4 nm, they display contrasting lateral dimensions. The findings reveal the pivotal role of Se precursor reactivity in determining two distinct synthesis pathways. Specifically, highly reactive precursors promote the formation of the nanocluster-lamellar assemblies, leading to the synthesis of 2D nanoribbons with elongated shapes. In contrast, mild precursors produce nanosheets from a tiny seed of 2D nuclei, and the lateral growth is regulated by chloride ions, rather than relying on nanocluster-lamellar assemblies or Cd(halide)2 -alkylamine templates, resulting in 2D nanocrystals with relatively shorter lengths. These findings significantly advance the understanding of the growth mechanism governing quantum-sized 2D semiconductor nanocrystals and offer valuable guidelines for their rational synthesis.
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Affiliation(s)
- Hyo Cheol Lee
- Department of Energy Science and EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST)Daegu42988Republic of Korea
| | - Megalamane S. Bootharaju
- Center for Nanoparticle ResearchInstitute for Basic Science (IBS)Seoul08826Republic of Korea
- School of Chemical and Biological Engineeringand Institute of Chemical ProcessesSeoul National UniversitySeoul08826Republic of Korea
| | - Kyunghoon Lee
- Department of Energy Science and EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST)Daegu42988Republic of Korea
| | - Hogeun Chang
- Center for Nanoparticle ResearchInstitute for Basic Science (IBS)Seoul08826Republic of Korea
- School of Chemical and Biological Engineeringand Institute of Chemical ProcessesSeoul National UniversitySeoul08826Republic of Korea
- Samsung Advanced Institute of TechnologySamsung ElectronicsSuwon16678Republic of Korea
| | - Seo Young Kim
- Department of Energy Science and EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST)Daegu42988Republic of Korea
| | - Eonhyoung Ahn
- Department of Energy Science and EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST)Daegu42988Republic of Korea
| | - Shi Li
- Department of Energy Science and EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST)Daegu42988Republic of Korea
| | - Byung Hyo Kim
- Center for Nanoparticle ResearchInstitute for Basic Science (IBS)Seoul08826Republic of Korea
- Department of Material Science and EngineeringSoongsil UniversitySeoul06978Republic of Korea
| | - Hyungju Ahn
- Pohang Accelerator LaboratoryPohang37673Republic of Korea
| | - Taeghwan Hyeon
- Center for Nanoparticle ResearchInstitute for Basic Science (IBS)Seoul08826Republic of Korea
- School of Chemical and Biological Engineeringand Institute of Chemical ProcessesSeoul National UniversitySeoul08826Republic of Korea
| | - Jiwoong Yang
- Department of Energy Science and EngineeringDaegu Gyeongbuk Institute of Science and Technology (DGIST)Daegu42988Republic of Korea
- Energy Science and Engineering Research CenterDaegu Gyeongbuk Institute of Science and Technology (DGIST)Daegu42988Republic of Korea
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6
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Llusar J, du Fossé I, Hens Z, Houtepen A, Infante I. Surface Reconstructions in II-VI Quantum Dots. ACS NANO 2024; 18:1563-1572. [PMID: 38169474 PMCID: PMC10795476 DOI: 10.1021/acsnano.3c09265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 01/05/2024]
Abstract
Although density functional theory (DFT) calculations have been crucial in our understanding of colloidal quantum dots (QDs), simulations are commonly carried out on QD models that are significantly smaller than those generally found experimentally. While smaller models allow for efficient study of local surface configurations, increasing the size of the QD model will increase the size or number of facets, which can in turn influence the energetics and characteristics of trap formation. Moreover, core-shell structures can only be studied with QD models that are large enough to accommodate the different layers with the correct thickness. Here, we use DFT calculations to study the electronic properties of QDs as a function of size, up to a diameter of ∼4.5 nm. We show that increasing the size of QD models traditionally used in DFT studies leads to a disappearance of the band gap and localization of the HOMO and LUMO levels on facet-specific regions of the QD surface. We attribute this to the lateral coupling of surface orbitals and the formation of surface bands. The introduction of surface vacancies and their a posteriori refilling with Z-type ligands leads to surface reconstructions that widen the band gap and delocalize both the HOMO and LUMO. These results show that the surface geometry of the facets plays a pivotal role in defining the electronic properties of the QD.
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Affiliation(s)
- Jordi Llusar
- BCMaterials,
Basque Center for Materials, Applications, and Nanostructures, UPV/EHU Science Park, Leioa 48940, Spain
| | - Indy du Fossé
- Department
of Chemical Engineering, Optoelectronic Materials, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The
Netherlands
| | - Zeger Hens
- Physics
and Chemistry of Nanostructures, Department of Chemistry, and Center
of Nano and Biophotonics, Ghent University, B-9000 Gent, Belgium
| | - Arjan Houtepen
- Department
of Chemical Engineering, Optoelectronic Materials, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The
Netherlands
| | - Ivan Infante
- BCMaterials,
Basque Center for Materials, Applications, and Nanostructures, UPV/EHU Science Park, Leioa 48940, Spain
- Ikerbasque
Basque Foundation for Science, Bilbao 48009, Spain
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7
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McKeever H, Patil NN, Palabathuni M, Singh S. Functional Alkali Metal-Based Ternary Chalcogenides: Design, Properties, and Opportunities. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:9833-9846. [PMID: 38107194 PMCID: PMC10720346 DOI: 10.1021/acs.chemmater.3c01652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 09/07/2023] [Indexed: 12/19/2023]
Abstract
The search for novel materials has recently brought research attention to alkali metal-based chalcogenides (ABZ) as a new class of semiconducting inorganic materials. Various theoretical and computational studies have highlighted many compositions of this class as ideal functional materials for application in energy conversion and storage devices. This Perspective discusses the expansive compositional landscape of ABZ compositions that inherently gives a wide spectrum of properties with great potential for application. In the present paper, we examine the technique of synthesizing this particular class of materials and explore their potential for compositional engineering in order to manipulate key functional properties. This study presents the notable findings that have been documented thus far in addition to outlining the potential avenues for implementation and the associated challenges they present. By fulfilling the sustainability requirements of being relativity earth-abundant, environmentally benign, and biocompatible, we anticipate a promising future for alkali metal chalcogenides. Through this Perspective, we aim to inspire continued research on this emerging class of materials, thereby enabling forthcoming breakthroughs in the realms of photovoltaics, thermoelectrics, and energy storage.
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Affiliation(s)
- Hannah McKeever
- Department of Chemical
Sciences and Bernal Institute, University of Limerick, V94 T9PX Limerick, Ireland
| | - Niraj Nitish Patil
- Department of Chemical
Sciences and Bernal Institute, University of Limerick, V94 T9PX Limerick, Ireland
| | - Manoj Palabathuni
- Department of Chemical
Sciences and Bernal Institute, University of Limerick, V94 T9PX Limerick, Ireland
| | - Shalini Singh
- Department of Chemical
Sciences and Bernal Institute, University of Limerick, V94 T9PX Limerick, Ireland
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8
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Cao W, Yakimov A, Qian X, Li J, Peng X, Kong X, Copéret C. Surface Sites and Ligation in Amine-capped CdSe Nanocrystals. Angew Chem Int Ed Engl 2023; 62:e202312713. [PMID: 37869935 DOI: 10.1002/anie.202312713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 10/24/2023]
Abstract
Converting colloidal nanocrystals (NCs) into devices for various applications is facilitated by designing and controlling their surface properties. One key strategy for tailoring surface properties is thus to choose tailored surface ligands. In that context, amines have been universally used, with the goal to improve NCs synthesis, processing and performances. However, understanding the nature of surface sites in amine-capped NCs remains challenging, due to the complex surface compositions as well as surface ligands dynamic. Here, we investigate both surface sites and amine ligation in CdSe NCs by combining advanced NMR spectroscopy and computational modelling. Notably, dynamic nuclear polarization (DNP) enhanced 113 Cd and 77 Se 1D NMR helps to identify both bulk and surface sites of NCs, while 113 Cd 2D NMR spectroscopy enables to resolve amines terminated sites on both Se-rich and nonpolar surfaces. In addition to directly bonding to surface sites, amines are shown to also interact through hydrogen-bonding with absorbed water as revealed by 15 N NMR, augmented with computations. The characterization methodology developed for this work provides unique molecular-level insight into the surface sites of a range of amine-capped CdSe NCs, and paves the way to identify structure-function relationships and rational approaches towards colloidal NCs with tailored properties.
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Affiliation(s)
- Weicheng Cao
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
- Department of Chemistry, Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Alexander Yakimov
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
| | - Xudong Qian
- Department of Chemistry, Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Jiongzhao Li
- Department of Chemistry, Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Xiaogang Peng
- Department of Chemistry, Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Xueqian Kong
- Institute of Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
- Department of Chemistry, Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou, 310058, China
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland
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9
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Baghdasaryan DA, Harutyunyan VA, Kazaryan EM, Sarkisyan HA, Petrosyan LS, Shahbazyan TV. Possibility of Exciton Bose-Einstein Condensation in CdSe Nanoplatelets. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2734. [PMID: 37836375 PMCID: PMC10574473 DOI: 10.3390/nano13192734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/01/2023] [Accepted: 10/06/2023] [Indexed: 10/15/2023]
Abstract
The quasi-two-dimensional exciton subsystem in CdSe nanoplatelets is considered. It is theoretically shown that Bose-Einstein condensation (BEC) of excitons is possible at a nonzero temperature in the approximation of an ideal Bose gas and in the presence of an "energy gap" between the ground and the first excited states of the two-dimensional exciton center of inertia of the translational motion. The condensation temperature (Tc) increases with the width of the "gap" between the ground and the first excited levels of size quantization. It is shown that when the screening effect of free electrons and holes on bound excitons is considered, the BEC temperature of the exciton subsystem increases as compared to the case where this effect is absent. The energy spectrum of the exciton condensate in a CdSe nanoplate is calculated within the framework of the weakly nonideal Bose gas approximation, considering the specifics of two-dimensional Born scattering.
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Affiliation(s)
- Davit A. Baghdasaryan
- Institute of Engineering and Physics, Russian-Armenian University, H. Emin 123, Yerevan 0051, Armenia; (D.A.B.); (V.A.H.); (E.M.K.)
| | - Volodya A. Harutyunyan
- Institute of Engineering and Physics, Russian-Armenian University, H. Emin 123, Yerevan 0051, Armenia; (D.A.B.); (V.A.H.); (E.M.K.)
| | - Eduard M. Kazaryan
- Institute of Engineering and Physics, Russian-Armenian University, H. Emin 123, Yerevan 0051, Armenia; (D.A.B.); (V.A.H.); (E.M.K.)
| | - Hayk A. Sarkisyan
- Institute of Engineering and Physics, Russian-Armenian University, H. Emin 123, Yerevan 0051, Armenia; (D.A.B.); (V.A.H.); (E.M.K.)
- Institute of Electronics and Telecommunications, Peter the Great Saint-Petersburg Polytechnical University, 195251 Saint-Petersburg, Russia
| | - Lyudvig S. Petrosyan
- Department of Physics, Jackson State University, Jackson, MS 39217, USA; (L.S.P.); (T.V.S.)
| | - Tigran V. Shahbazyan
- Department of Physics, Jackson State University, Jackson, MS 39217, USA; (L.S.P.); (T.V.S.)
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10
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Marino E, Jiang Z, Kodger TE, Murray CB, Schall P. Controlled Assembly of CdSe Nanoplatelet Thin Films and Nanowires. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:12533-12540. [PMID: 37561597 PMCID: PMC10501200 DOI: 10.1021/acs.langmuir.3c00933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 07/03/2023] [Indexed: 08/12/2023]
Abstract
We assemble semiconductor CdSe nanoplatelets (NPs) at the air/liquid interface into 2D monolayers several micrometers wide, distinctly displaying nematic order. We show that this configuration is the most favorable energetically and that the edge-to-edge distance between neighboring NPs can be tuned by ligand exchange without disrupting film topology and nanoparticle orientation. We explore the rich assembly phase space by using depletion interactions to direct the formation of 1D nanowires from stacks of NPs. The improved control and understanding of the assembly of semiconductor NPs offers opportunities for the development of cheaper optoelectronic devices that rely on 1D or 2D charge delocalization throughout the assembled monolayers and nanowires.
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Affiliation(s)
- Emanuele Marino
- Van
der Waals−Zeeman Institute, University
of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
- Department
of Chemistry, University of Pennsylvania, 231 S. 34th St., 19104 Philadelphia, (Pennsylvania), United States
- Dipartimento
di Fisica e Chimica, Università degli
Studi di Palermo, Via Archirafi 36, 90123 Palermo, Italy
| | - Zhiqiao Jiang
- Department
of Chemistry, University of Pennsylvania, 231 S. 34th St., 19104 Philadelphia, (Pennsylvania), United States
- Department
of Materials Science and Engineering, University
of Pennsylvania, 3231 Walnut Street, 19104 Philadelphia (Pennsylvania), United States
| | - Thomas E. Kodger
- Van
der Waals−Zeeman Institute, University
of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
- Physical
Chemistry and Soft Matter, Wageningen University
and Research, Stippeneng 4, 6708WE Wageningen, The Netherlands
| | - Christopher B. Murray
- Department
of Chemistry, University of Pennsylvania, 231 S. 34th St., 19104 Philadelphia, (Pennsylvania), United States
- Department
of Materials Science and Engineering, University
of Pennsylvania, 3231 Walnut Street, 19104 Philadelphia (Pennsylvania), United States
| | - Peter Schall
- Van
der Waals−Zeeman Institute, University
of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
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11
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Liu H, Chen P, Zhang X, Wang X, He T, Chen R. Lateral surface passivation of CdSe nanoplatelets through crown management. NANOSCALE 2023; 15:14140-14145. [PMID: 37584662 DOI: 10.1039/d3nr03133k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Two-dimensional colloidal CdSe nanoplatelets (NPLs) have been considered as ideal emitting materials for high performance light-emitting devices due to their excellent optical properties. However, the understanding of defect related radiative and nonradiative recombination centers in CdSe NPLs is still far from sufficient, especially their physical distribution locations. In this work, CdSe core and CdSe/CdS core/crown NPLs have been successfully synthesized and their optical properties have been characterized by laser spectroscopies. It is found that the photoluminescence quantum yield of CdSe NPLs is improved by a factor of 4 after the growth of the CdS crown. At low temperatures, the change in the ratio of low and high energy emission intensities from NPLs suggests that the radiative recombination centers are mainly located on the lateral surface of the samples. This finding is further confirmed by the surface passivation experiment. Meanwhile, the nonradiative recombination centers of NPLs located on the lateral surface are also confirmed by ligand exchange. These results demonstrate the importance of understanding the optical properties of the lateral surface of NPLs, which are important for the design of material structures for optoelectronic applications.
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Affiliation(s)
- Huan Liu
- Harbin Institute of Technology, Harbin 150001, China
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Peixian Chen
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
| | - Xuanyu Zhang
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Xiongbin Wang
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Tingchao He
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
| | - Rui Chen
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
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12
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Lei H, Li J, Kong X, Wang L, Peng X. Toward Surface Chemistry of Semiconductor Nanocrystals at an Atomic-Molecular Level. Acc Chem Res 2023. [PMID: 37413974 DOI: 10.1021/acs.accounts.3c00185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
ConspectusProperties of colloidal semiconductor nanocrystals with a single-crystalline structure are largely dominated by their surface structure at an atomic-molecular level, which is not well understood and controlled, due to a lack of experimental tools. However, if viewing the nanocrystal surface as three relatively independent spatial zones (i.e., crystal facets, inorganic-ligands interface, and ligands monolayer), we may approach an atomic-molecular level by coupling advanced experimental techniques and theoretical calculations.Semiconductor nanocrystals of interest are mainly based on compound semiconductors and mostly in two (or related) crystal structures, namely zinc-blende and wurtzite, which results in a small group of common low-index crystal facets. These low-index facets, from a surface-chemistry perspective, can be further classified into polar and nonpolar ones. Albeit far from being successful, the controlled formation of either polar or nonpolar facets is available for cadmium chalcogenide nanocrystals. Such facet-controlled systems offer a reliable basis for studying the inorganic-ligands interface. For convenience, here facet-controlled nanocrystals refer to a special class of shape-controlled ones, in which shape control is at an atomic level, instead of those with poorly defined facets (e.g., typical spheroids, nanorods, etc).Experimental and theoretical results reveal that type and bonding mode of surface ligands on nanocrystals is facet-specific and often beyond Green's classification (X-type, Z-type, and L-type). For instance, alkylamines bond strongly to the anion-terminated (0001) wurtzite facet in the form of ammonium ions, with three hydrogens of an ammonium ion bonding to three adjacent surface anion sites. With theoretically assessable experimental data, facet-ligands pairing can be identified using density functional theory (DFT) calculations. To make the pairing meaningful, possible forms of all potential ligands in the system need to be examined systematically, revealing the advantage of simple solution systems.Unlike the other two spatial zones, the ligands monolayer is disordered and dynamic at an atomic level. Thus, an understanding of the ligands monolayer on a molecular scale is sufficient for many cases. For colloidal nanocrystals stably coordinated with surface ligands, their solution properties are dictated by the ligands monolayer. Experimental and theoretical results reveal that solubility of a nanocrystal-ligands complex is an interplay between the intramolecular entropy of the ligands monolayer and intermolecular interactions of the ligands/nanocrystals. By introducing entropic ligands, solubility of nanocrystal-ligands complexes can be universally boosted by several orders of magnitude, i.e., up to >1 g/mL in typical organic solvents. Molecular environment in the pseudophase surrounding each nanocrystal plays a critical role in its chemical, photochemical, and photophysical properties.For some cases, such as the synthesis of high-quality nanocrystals, all three spatial zones of the nanocrystal surface must be taken into account. By optimizing nanocrystal surface at an atomic-molecular level, semiconductor nanocrystals with monodisperse size and facet structure become available recently through either direct synthesis or afterward facet reconstruction, implying full realization of their size-dependent properties.
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Affiliation(s)
- Hairui Lei
- Key Laboratory of Excited-State Materials of Zhejiang Province, and Department of Chemistry, Zhejiang University, Hangzhou, 310058, China
| | - Jiongzhao Li
- Key Laboratory of Excited-State Materials of Zhejiang Province, and Department of Chemistry, Zhejiang University, Hangzhou, 310058, China
| | - Xueqian Kong
- Institute of Translational Medicine, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Linjun Wang
- Key Laboratory of Excited-State Materials of Zhejiang Province, and Department of Chemistry, Zhejiang University, Hangzhou, 310058, China
| | - Xiaogang Peng
- Key Laboratory of Excited-State Materials of Zhejiang Province, and Department of Chemistry, Zhejiang University, Hangzhou, 310058, China
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13
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Rodà C, Di Giacomo A, Tasende Rodríguez LC, M CS, Leemans J, Hens Z, Geiregat P, Moreels I. Colloidal CdSe/CdS Core/Crown Nanoplatelets for Efficient Blue Light Emission and Optical Amplification. NANO LETTERS 2023; 23:3224-3230. [PMID: 37125440 DOI: 10.1021/acs.nanolett.2c05061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The application of CdSe nanoplatelets (NPLs) in the ultraviolet/blue region remains an open challenge due to charge trapping typically leading to limited photoluminescence quantum efficiency (PL QE) and sub-bandgap emission in core-only NPLs. Here, we synthesized 3.5 monolayer core/crown CdSe/CdS NPLs with various crown dimensions, exhibiting saturated blue emission and PL QE up to 55%. Compared to core-only NPLs, the PL intensity decays monoexponentially over two decades due to suppressed deep trapping and delayed emission. In both core-only and core/crown NPLs we observe biexciton-mediated optical gain between 470 and 510 nm, with material gain coefficients up to 7900 cm-1 and consistently lower gain thresholds in crowned NPLs. Gain lifetimes are limited to 40 ps, due to residual ultrafast trapping and higher exciton densities at threshold. Our results provide guidelines for rational optimization of thin CdSe NPLs toward lighting and light-amplification applications.
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Affiliation(s)
- Carmelita Rodà
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Technologiepark, Zwijnaarde 15, 9052 Gent, Belgium
| | - Alessio Di Giacomo
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Technologiepark, Zwijnaarde 15, 9052 Gent, Belgium
| | - Lucía Camila Tasende Rodríguez
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Technologiepark, Zwijnaarde 15, 9052 Gent, Belgium
| | - Chandra Sekhar M
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Technologiepark, Zwijnaarde 15, 9052 Gent, Belgium
| | - Jari Leemans
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Technologiepark, Zwijnaarde 15, 9052 Gent, Belgium
| | - Zeger Hens
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Technologiepark, Zwijnaarde 15, 9052 Gent, Belgium
| | - Pieter Geiregat
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Technologiepark, Zwijnaarde 15, 9052 Gent, Belgium
| | - Iwan Moreels
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium
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14
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Schiettecatte P, Singh S, Zhou P, Hens Z. The Dynamic Interaction of Surfactants with Colloidal Molybdenum Disulfide Nanosheets Calls for Thermodynamic Stabilization by Solvents. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:6568-6579. [PMID: 37095622 DOI: 10.1021/acs.langmuir.3c00546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Top-down liquid-phase exfoliation (LPE) and bottom-up hot-injection synthesis are scalable methods to produce colloids of two-dimensional (2D) van der Waals (vdW) solids. Generally thought off as two entirely different fields, we show that similar stabilization mechanisms apply to colloids of molybdenum disulfide (MoS2) produced by both methods. By screening the colloidal stability of MoS2 produced in a hot-injection synthesis in a wide range of solvents, we observe that colloidal stability can be understood based on solution thermodynamics, wherein matching the solubility parameter of solvent and nanomaterial maximizes colloidal stability. Identical to MoS2 produced through LPE, optimal solvents to disperse MoS2 produced from the bottom-up have similar solubility parameters of ≈22 MPa1/2 and include aromatic solvents with polar functionalities, such as o-dichlorobenzene, and polar aprotic solvents, such as N,N-dimethylformamide. We further complemented our findings by nuclear magnetic resonance (NMR) spectrscopy, highlighting that organic surfactants, such as oleylamine and oleic acid, have a minimal affinity toward the nanocrystal surface and engage in a highly dynamic adsorption/desorption equilibrium. We thus conclude that hot injection yields MoS2 colloids with comparable surfaces as those produced by LPE. These similarities might offer the prospect of using established procedures developed for LPE nanomaterials to postprocess colloidally synthesized dispersions of 2D colloids as processable inks.
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Affiliation(s)
- Pieter Schiettecatte
- Physics and Chemistry of Nanostructures, Ghent University, Ghent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Ghent 9000, Belgium
| | - Shalini Singh
- Department of Chemical Sciences, Unviersity of Limerick, Limerick V94T9PX, Ireland
| | - Pengshang Zhou
- Physics and Chemistry of Nanostructures, Ghent University, Ghent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Ghent 9000, Belgium
- Jiangnan University, Wuxi 214122, China
| | - Zeger Hens
- Physics and Chemistry of Nanostructures, Ghent University, Ghent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Ghent 9000, Belgium
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15
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Diroll BT, Guzelturk B, Po H, Dabard C, Fu N, Makke L, Lhuillier E, Ithurria S. 2D II-VI Semiconductor Nanoplatelets: From Material Synthesis to Optoelectronic Integration. Chem Rev 2023; 123:3543-3624. [PMID: 36724544 DOI: 10.1021/acs.chemrev.2c00436] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The field of colloidal synthesis of semiconductors emerged 40 years ago and has reached a certain level of maturity thanks to the use of nanocrystals as phosphors in commercial displays. In particular, II-VI semiconductors based on cadmium, zinc, or mercury chalcogenides can now be synthesized with tailored shapes, composition by alloying, and even as nanocrystal heterostructures. Fifteen years ago, II-VI semiconductor nanoplatelets injected new ideas into this field. Indeed, despite the emergence of other promising semiconductors such as halide perovskites or 2D transition metal dichalcogenides, colloidal II-VI semiconductor nanoplatelets remain among the narrowest room-temperature emitters that can be synthesized over a wide spectral range, and they exhibit good material stability over time. Such nanoplatelets are scientifically and technologically interesting because they exhibit optical features and production advantages at the intersection of those expected from colloidal quantum dots and epitaxial quantum wells. In organic solvents, gram-scale syntheses can produce nanoparticles with the same thicknesses and optical properties without inhomogeneous broadening. In such nanoplatelets, quantum confinement is limited to one dimension, defined at the atomic scale, which allows them to be treated as quantum wells. In this review, we discuss the synthetic developments, spectroscopic properties, and applications of such nanoplatelets. Covering growth mechanisms, we explain how a thorough understanding of nanoplatelet growth has enabled the development of nanoplatelets and heterostructured nanoplatelets with multiple emission colors, spatially localized excitations, narrow emission, and high quantum yields over a wide spectral range. Moreover, nanoplatelets, with their large lateral extension and their thin short axis and low dielectric surroundings, can support one or several electron-hole pairs with large exciton binding energies. Thus, we also discuss how the relaxation processes and lifetime of the carriers and excitons are modified in nanoplatelets compared to both spherical quantum dots and epitaxial quantum wells. Finally, we explore how nanoplatelets, with their strong and narrow emission, can be considered as ideal candidates for pure-color light emitting diodes (LEDs), strong gain media for lasers, or for use in luminescent light concentrators.
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Affiliation(s)
- Benjamin T Diroll
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Burak Guzelturk
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Hong Po
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Corentin Dabard
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Ningyuan Fu
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Lina Makke
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Emmanuel Lhuillier
- Sorbonne Université, CNRS, Institut des NanoSciences de Paris, INSP, 75005 Paris, France
| | - Sandrine Ithurria
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
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16
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VanOrman ZA, Weiss R, Bieber AS, Chen B, Nienhaus L. Mechanistic insight into CdSe nanoplatelet-sensitized upconversion: size and stacking induced effects. Chem Commun (Camb) 2023; 59:322-325. [PMID: 36511180 DOI: 10.1039/d2cc04694f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
CdSe nanoplatelets (NPLs) have been reported as triplet sensitizers for photon upconversion (UC). However, their UC quantum yields lag behind more conventional systems. Here, we take advantage of their one-dimensional quantum confinement to decouple effects caused by the energetic driving force and lateral size. A surprising anti-correlation between the power threshold Ith and the UC quantum yield based on the NPL size is found. We attribute this result to two distinct triplet-triplet annihilation mechanisms based on the NPL lateral dimension and degree of NPL stacking-mediated either by molecular diffusion or triplet energy diffusion.
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Affiliation(s)
- Zachary A VanOrman
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Rachel Weiss
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Alexander S Bieber
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Banghao Chen
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
| | - Lea Nienhaus
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA.
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17
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Petersen N, Girard M, Riedinger A, Valsson O. The Crucial Role of Solvation Forces in the Steric Stabilization of Nanoplatelets. NANO LETTERS 2022; 22:9847-9853. [PMID: 36493312 PMCID: PMC9801426 DOI: 10.1021/acs.nanolett.2c02848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 12/02/2022] [Indexed: 06/17/2023]
Abstract
The steric stability of inorganic colloidal particles in an apolar solvent is usually described in terms of the balance between three contributions: the van der Waals attraction, the free energy of mixing, and the ligand compression. However, in the case of nanoparticles, the discrete nature of the ligand shell and the solvent has to be taken into account. Cadmium selenide nanoplatelets are a special case. They combine a weak van der Waals attraction and a large facet to particle size ratio. We use coarse grained molecular dynamics simulations of nanoplatelets in octane to demonstrate that solvation forces are strong enough to induce the formation of nanoplatelet stacks and by that have a crucial impact on the steric stability. In particular, we demonstrate that for sufficiently large nanoplatelets, solvation forces are proportional to the interacting facet area, and their strength is intrinsically tied to the softness of the ligand shell.
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Affiliation(s)
- Nanning Petersen
- Max
Planck Institute for Polymer Research, Mainz D-55128, Germany
| | - Martin Girard
- Max
Planck Institute for Polymer Research, Mainz D-55128, Germany
| | | | - Omar Valsson
- Max
Planck Institute for Polymer Research, Mainz D-55128, Germany
- Department
of Chemistry, University of North Texas, Denton, Texas 76201, United States
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18
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Anand A, Zaffalon ML, Cova F, Pinchetti V, Khan AH, Carulli F, Brescia R, Meinardi F, Moreels I, Brovelli S. Optical and Scintillation Properties of Record-Efficiency CdTe Nanoplatelets toward Radiation Detection Applications. NANO LETTERS 2022; 22:8900-8907. [PMID: 36331389 PMCID: PMC9706671 DOI: 10.1021/acs.nanolett.2c02975] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/26/2022] [Indexed: 06/16/2023]
Abstract
Colloidal CdTe nanoplatelets featuring a large absorption coefficient and ultrafast tunable luminescence coupled with heavy-metal-based composition present themselves as highly desirable candidates for radiation detection technologies. Historically, however, these nanoplatelets have suffered from poor emission efficiency, hindering progress in exploring their technological potential. Here, we report the synthesis of CdTe nanoplatelets possessing a record emission efficiency of 9%. This enables us to investigate their fundamental photophysics using ultrafast transient absorption, temperature-controlled photoluminescence, and radioluminescence measurements, elucidating the origins of exciton- and defect-related phenomena under both optical and ionizing excitation. For the first time in CdTe nanoplatelets, we report the cumulative effects of a giant oscillator strength transition and exciton fine structure. Simultaneously, thermally stimulated luminescence measurements reveal the presence of both shallow and deep trap states and allow us to disclose the trapping and detrapping dynamics and their influence on the scintillation properties.
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Affiliation(s)
- Abhinav Anand
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano-Bicocca, via R. Cozzi 55, 20125Milano, Italy
| | - Matteo L. Zaffalon
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano-Bicocca, via R. Cozzi 55, 20125Milano, Italy
| | - Francesca Cova
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano-Bicocca, via R. Cozzi 55, 20125Milano, Italy
| | - Valerio Pinchetti
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano-Bicocca, via R. Cozzi 55, 20125Milano, Italy
| | | | - Francesco Carulli
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano-Bicocca, via R. Cozzi 55, 20125Milano, Italy
| | - Rosaria Brescia
- Electron
Microscopy Facility, Istituto Italiano di
Tecnologia, Via Morego 30, 16163Genova, Italy
| | - Francesco Meinardi
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano-Bicocca, via R. Cozzi 55, 20125Milano, Italy
| | - Iwan Moreels
- Department
of Chemistry, Ghent University, 9000Ghent, Belgium
- Electron
Microscopy Facility, Istituto Italiano di
Tecnologia, Via Morego 30, 16163Genova, Italy
| | - Sergio Brovelli
- Dipartimento
di Scienza dei Materiali, Università
degli Studi di Milano-Bicocca, via R. Cozzi 55, 20125Milano, Italy
- Electron
Microscopy Facility, Istituto Italiano di
Tecnologia, Via Morego 30, 16163Genova, Italy
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19
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Hu A, Bai P, Zhu Y, Tang Z, Xiao L, Gao Y. Controlled Core/Crown Growth Enables Blue-Emitting Colloidal Nanoplatelets with Efficient and Pure Photoluminescence. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2204120. [PMID: 36135780 DOI: 10.1002/smll.202204120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/18/2022] [Indexed: 06/16/2023]
Abstract
Colloidal semiconductor CdSe nanoplatelets (NPLs) feature ultranarrow and anisotropic emissions. However, the optical performance of blue-emitting NPLs is deteriorated by trap states, currently exhibiting tainted emissions and inferior photoluminescence quantum yields (PLQYs). Here, near trap-free blue-emitting NPLs are achieved by the controlled growth of the core/crown. Deep trap states in NPLs can be partially suppressed with the asymmetrical crown growth and are further suppressed with the growth of the small core and the alloyed symmetrical crown, yielding NPLs with pure blue emissions and near-unity PLQYs. Exciton dynamic research based on these NPLs indicates that the trap emission stems from surface traps. Besides, light-emitting diodes exhibiting ultranarrow emission centered around 461 nm with full-width-at-half-maximums down to 11 nm are fabricated using these NPLs.
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Affiliation(s)
- An Hu
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P. R. China
| | - Peng Bai
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P. R. China
| | - Yunke Zhu
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P. R. China
| | - Zhenyu Tang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P. R. China
| | - Lixin Xiao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P. R. China
| | - Yunan Gao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, P. R. China
- Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing, 100871, P. R. China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, P. R. China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu, 226010, P. R. China
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20
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Li F, Klepzig LF, Keppler N, Behrens P, Bigall NC, Menzel H, Lauth J. Layer-by-Layer Deposition of 2D CdSe/CdS Nanoplatelets and Polymers for Photoluminescent Composite Materials. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:11149-11159. [PMID: 36067458 DOI: 10.1021/acs.langmuir.2c00455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Two-dimensional (2D) semiconductor nanoplatelets (NPLs) are strongly photoluminescent materials with interesting properties for optoelectronics. Especially their narrow photoluminescence paired with a high quantum yield is promising for light emission applications with high color purity. However, retaining these features in solid-state thin films together with an efficient encapsulation of the NPLs is a challenge, especially when trying to achieve high-quality films with a defined optical density and low surface roughness. Here, we show photoluminescent polymer-encapsulated inorganic-organic nanocomposite coatings of 2D CdSe/CdS NPLs in poly(diallyldimethylammonium chloride) (PDDA) and poly(ethylenimine) (PEI), which are prepared by sequential layer-by-layer (LbL) deposition. The electrostatic interaction between the positively charged polyelectrolytes and aqueous phase-transferred NPLs with negatively charged surface ligands is used as a driving force to achieve self-assembled nanocomposite coatings with a well-controlled layer thickness and surface roughness. Increasing the repulsive forces between the NPLs by increasing the pH value of the dispersion leads to the formation of nanocomposites with all NPLs arranging flat on the substrate, while the surface roughness of the 165 nm (50 bilayers) thick coating decreases to Ra = 14 nm. The photoluminescence properties of the nanocomposites are determined by the atomic layer thickness of the NPLs and the 11-mercaptoundecanoic acid ligand used for their phase transfer. Both the full width at half-maximum (20.5 nm) and the position (548 nm) of the nanocomposite photoluminescence are retained in comparison to the colloidal CdSe/CdS NPLs in aqueous dispersion, while the measured photoluminescence quantum yield of 5% is competitive to state-of-the-art nanomaterial coatings. Our approach yields stable polymer-encapsulated CdSe/CdS NPLs in smooth coatings with controllable film thickness, rendering the LbL deposition technique a powerful tool for the fabrication of solid-state photoluminescent nanocomposites.
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Affiliation(s)
- Fuzhao Li
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute for Technical Chemistry, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Lars F Klepzig
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
| | - Nils Keppler
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Inorganic Chemistry, Leibniz Universität Hannover, Callinstraße 9, 30167 Hannover, Germany
| | - Peter Behrens
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Inorganic Chemistry, Leibniz Universität Hannover, Callinstraße 9, 30167 Hannover, Germany
- Laboratory of Nano and Quantum Engineering, Schneiderberg 39, 30167 Hannover, Germany
| | - Nadja C Bigall
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
- Laboratory of Nano and Quantum Engineering, Schneiderberg 39, 30167 Hannover, Germany
| | - Henning Menzel
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute for Technical Chemistry, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Jannika Lauth
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
- Laboratory of Nano and Quantum Engineering, Schneiderberg 39, 30167 Hannover, Germany
- Institute of Physical and Theoretical Chemistry, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
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21
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Wang N, Cheong S, Yoon DE, Lu P, Lee H, Lee YK, Park YS, Lee DC. Efficient, Selective CO 2 Photoreduction Enabled by Facet-Resolved Redox-Active Sites on Colloidal CdS Nanosheets. J Am Chem Soc 2022; 144:16974-16983. [PMID: 36007150 DOI: 10.1021/jacs.2c06164] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Advances in nanotechnology have enabled precise design of catalytic sites for CO2 photoreduction, pushing product selectivity to near unity. However, activity of most nanostructured photocatalysts remains underwhelming due to fast recombination of photogenerated electron-hole pairs and sluggish hole transfer. To address these issues, we construct colloidal CdS nanosheets (NSs) with the large basal planes terminated by S2- atomic layers as intrinsic photocatalysts (CdS-S2- NSs). Experimental investigation reveals that the S2- termination endows ultrathin CdS-S2- NSs with facet-resolved redox-catalytic sites: oxidation occurs on S2--terminated large basal facets and reduction happens on side facets. Such an allocation of redox sites not only promotes spatial separation of photoinduced electrons and holes but also facilitates balanced extraction of holes and electrons by shortening the hole diffusion distance along the (001) direction of the ultrathin NSs. Consequently, the CdS-S2- NSs exhibit superb performance for photocatalytic CO2-to-CO conversion, which was verified by the isotope-labeled experiments to be a record-breaking performance: a CO selectivity of 99%, a CO formation rate of 2.13 mol g-1 h-1, and an effective apparent quantum efficiency of 42.1% under the irradiation (340 to 450 nm) of a solar simulator (AM 1.5G). The breakthrough performance achieved in this work provides novel insights into the precise design of nanostructures for selective and efficient CO2 photoreduction.
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Affiliation(s)
- Nianfang Wang
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury, Energy & Environmental Research Center (EERC), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Seokhyeon Cheong
- Division of Energy and Environment Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea
| | - Da-Eun Yoon
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury, Energy & Environmental Research Center (EERC), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Pan Lu
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury, Energy & Environmental Research Center (EERC), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hyunjoo Lee
- Division of Energy and Environment Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea.,Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Young Kuk Lee
- Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Republic of Korea
| | - Young-Shin Park
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury, Energy & Environmental Research Center (EERC), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Doh C Lee
- Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury, Energy & Environmental Research Center (EERC), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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22
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Weiss R, VanOrman ZA, Sullivan CM, Nienhaus L. A Sensitizer of Purpose: Generating Triplet Excitons with Semiconductor Nanocrystals. ACS MATERIALS AU 2022; 2:641-654. [PMID: 36855545 PMCID: PMC9928406 DOI: 10.1021/acsmaterialsau.2c00047] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 11/28/2022]
Abstract
The process of photon upconversion promises importance for many optoelectronic applications, as it can result in higher efficiencies and more effective photon management. Upconversion via triplet-triplet annihilation (TTA) occurs at low incident powers and at high efficiencies, requirements for integration into existing optoelectronic devices. Semiconductor nanocrystals are a diverse class of triplet sensitizers with advantages over traditional molecular sensitizers such as energetic tunability and minimal energy loss during the triplet sensitization process. In this Perspective, we review current progress in semiconductor nanocrystal triplet sensitization, specifically focusing on the nanocrystal, the ligand shell which surrounds the nanocrystal, and progress in solid-state sensitization. Finally, we discuss potential areas of improvement which could result in more efficient upconversion systems sensitized by semiconductor nanocrystals. Specifically, we focus on the development of solid-state TTA upconversion systems, elucidation of the energy transfer mechanisms from nanocrystal to transmitter ligand which underpin the upconversion process and propose novel configurations of nanocrystal-sensitized systems.
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23
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Lee J, Yoo K, Liu H, Kang J. Sensitivity improvement of hybrid active layer containing 2D nanoplatelets for indirect x-ray detector. NANOTECHNOLOGY 2022; 33:405701. [PMID: 35760045 DOI: 10.1088/1361-6528/ac7c26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
In this paper, we attempted to improve the detection sensitivity of an indirect x-ray detector through using a hybrid active layer composed of a poly [N-90-heptadecanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothiadiazole)] (PCDTBT) organic semiconductor and cadmium selenide nanoplatelets (CdSe NPLs) colloidal inorganic semiconductors. First, different blending ratio in the active layer (i.e. 2:1, 1:1, 1:2 and 1:3) of PCDTBT:CdSe NPL were examined, a sensitivity of 89.5μC·Gyair-1·cm-2was achieved using a 1:1 ratio due to the low series resistance (RS) and defect density in this configuration. Then, the oleic acid (OA) that was initially applied in the CdSe NPL surface was replaced with pyridine ligands, this was done because the pyridine ligand is a short-chain ligand that can help charge transfer by reducing the distance between NPLs in the active layer. In addition, an experiment was conducted to determine the optimal ligand exchange time. A detector with an PCDTBT:CdSe NPL active layer fabricated using pyridine ligand exchange achieved a sensitivity of 219.8μC·Gyair-1·cm-2after an exchange time of 12 h, this is an improvement of 155% compared to the detector using a PCDTBT:CdSe NPL with the original OA ligands. Lastly, the optimal thickness for the PCDTBT:CdSe NPL active layer was investigated. The highest mobility of 7.60 × 10- 6cm2/V·s was recorded after fabricating the layer using spin-coating at 1900 rpm, the highest sensitivity of 314.0μC·Gyair-1·cm-2was also achieved under these conditions. Compared to the initial state of the detector, our modifications improved the sensitivity of the PCDTBT:CdSe NPL detector by 251%.
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Affiliation(s)
- Jehoon Lee
- Department of Electronic and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea
| | - Kyunghan Yoo
- Department of Electronic and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea
| | - Hailiang Liu
- Department of Electronic and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea
| | - Jungwon Kang
- Department of Electronic and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea
- Convergence Semiconductor Research Center, Dankook University, Yongin-si 16890, Republic of Korea
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24
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Schwotzer F, Horak J, Senkovska I, Schade E, Gorelik TE, Wollmann P, Anh ML, Ruck M, Kaiser U, Weidinger IM, Kaskel S. Cooperative Assembly of 2D-MOF Nanoplatelets into Hierarchical Carpets and Tubular Superstructures for Advanced Air Filtration. Angew Chem Int Ed Engl 2022; 61:e202117730. [PMID: 35285126 PMCID: PMC9315001 DOI: 10.1002/anie.202117730] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Indexed: 11/10/2022]
Abstract
Clean air is an indispensable prerequisite for human health. The capture of small toxic molecules requires the development of advanced materials for air filtration. Two-dimensional nanomaterials offer highly accessible surface areas but for real-world applications their assembly into well-defined hierarchical mesostructures is essential. DUT-134(Cu) ([Cu2 (dttc)2 ]n , dttc=dithieno[3,2-b : 2',3'-d]thiophene-2,6-dicarboxylate]) is a metal-organic framework forming platelet-shaped particles, that can be organized into complex structures, such as millimeter large free-standing layers (carpets) and tubes. The structured material demonstrates enhanced accessibility of open metal sites and significantly enhanced H2 S adsorption capacity in gas filtering tests compared with traditional bulk analogues.
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Affiliation(s)
- Friedrich Schwotzer
- Inorganic Chemistry Center I, Technische Universität Dresden, Bergstr. 66, 01069, Dresden, Germany
| | - Jacob Horak
- Inorganic Chemistry Center I, Technische Universität Dresden, Bergstr. 66, 01069, Dresden, Germany
| | - Irena Senkovska
- Inorganic Chemistry Center I, Technische Universität Dresden, Bergstr. 66, 01069, Dresden, Germany
| | - Elke Schade
- IWS Dresden, Winterbergstr. 28, 01277, Dresden, Germany
| | - Tatiana E Gorelik
- Electron Microscopy Group of Materials Science (EMMS), Central Facility for Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Philipp Wollmann
- Electrochemistry, Technische Universität Dresden, Zellescher Weg 19, 01069, Dresden, Germany
| | - Mai Lê Anh
- Inorganic Chemistry II, Technische Universität Dresden, Bergstr. 66, 01069, Dresden, Germany
| | - Michael Ruck
- Inorganic Chemistry II, Technische Universität Dresden, Bergstr. 66, 01069, Dresden, Germany.,Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187, Dresden, Germany
| | - Ute Kaiser
- Electron Microscopy Group of Materials Science (EMMS), Central Facility for Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Inez M Weidinger
- Electrochemistry, Technische Universität Dresden, Zellescher Weg 19, 01069, Dresden, Germany
| | - Stefan Kaskel
- Inorganic Chemistry Center I, Technische Universität Dresden, Bergstr. 66, 01069, Dresden, Germany.,IWS Dresden, Winterbergstr. 28, 01277, Dresden, Germany
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25
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van der Bok JC, Prins PT, Montanarella F, Maaskant DN, Brzesowsky FA, van der Sluijs MM, Salzmann BBV, Rabouw FT, Petukhov AV, De Mello Donega C, Vanmaekelbergh D, Meijerink A. In Situ Optical and X-ray Spectroscopy Reveals Evolution toward Mature CdSe Nanoplatelets by Synergetic Action of Myristate and Acetate Ligands. J Am Chem Soc 2022; 144:8096-8105. [PMID: 35482030 PMCID: PMC9100465 DOI: 10.1021/jacs.2c00423] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The growth of two-dimensional platelets of the CdX family (X = S, Se, or Te) in an organic solvent requires the presence of both long- and short-chain ligands. This results in nanoplatelets of atomically precise thickness and long-chain ligand-stabilized Cd top and bottom surfaces. The platelets show a bright and spectrally pure luminescence. Despite the enormous interest in CdX platelets for optoelectronics, the growth mechanism is not fully understood. Riedinger et al. studied the reaction without a solvent and showed the favorable role for short-chain carboxylates for growth in two dimensions. Their model, based on the total energy of island nucleation, shows favored side facet growth versus growth on the top and bottom surfaces. However, several aspects of the synthesis under realistic conditions are not yet understood: Why are both short- and long-chain ligands required to obtain platelets? Why does the synthesis result in both isotropic nanocrystals and platelets? At which stage of the reaction is there bifurcation between isotropic and 2D growth? Here, we report an in situ study of the CdSe nanoplatelet reaction under practical synthesis conditions. We show that without short-chain ligands, both isotropic and mini-nanoplatelets form in the early stage of the process. However, most remaining precursors are consumed in isotropic growth. Addition of acetate induces a dramatic shift toward nearly exclusive 2D growth of already existing mini-nanoplatelets. Hence, although myristate stabilizes mini-nanoplatelets, mature nanoplatelets only grow by a subtle interplay between myristate and acetate, the latter catalyzes fast lateral growth of the side facets of the mini-nanoplatelets.
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Affiliation(s)
- Johanna C van der Bok
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - P Tim Prins
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - Federico Montanarella
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - D Nicolette Maaskant
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - Floor A Brzesowsky
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - Maaike M van der Sluijs
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - Bastiaan B V Salzmann
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - Freddy T Rabouw
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - Andrei V Petukhov
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands.,Laboratory of Physical Chemistry, Eindhoven University of Technology, AZ Eindhoven 5612, The Netherlands
| | - Celso De Mello Donega
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - Daniel Vanmaekelbergh
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
| | - Andries Meijerink
- Debye Institute for Nanomaterials Science, Utrecht University, CS Utrecht 3584, The Netherlands
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26
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Schwotzer F, Horak J, Senkovska I, Schade E, Gorelik TE, Wollmann P, Anh ML, Ruck M, Kaiser U, Weidinger IM, Kaskel S. Cooperative Assembly of 2D‐MOF Nanoplatelets into Hierarchical Carpets and Tubular Superstructures for Advanced Air Filtration. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202117730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Friedrich Schwotzer
- Inorganic Chemistry Center I Technische Universität Dresden Bergstr. 66 01069 Dresden Germany
| | - Jacob Horak
- Inorganic Chemistry Center I Technische Universität Dresden Bergstr. 66 01069 Dresden Germany
| | - Irena Senkovska
- Inorganic Chemistry Center I Technische Universität Dresden Bergstr. 66 01069 Dresden Germany
| | - Elke Schade
- IWS Dresden Winterbergstr. 28 01277 Dresden Germany
| | - Tatiana E. Gorelik
- Electron Microscopy Group of Materials Science (EMMS) Central Facility for Electron Microscopy Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Philipp Wollmann
- Electrochemistry Technische Universität Dresden Zellescher Weg 19 01069 Dresden Germany
| | - Mai Lê Anh
- Inorganic Chemistry II Technische Universität Dresden Bergstr. 66 01069 Dresden Germany
| | - Michael Ruck
- Inorganic Chemistry II Technische Universität Dresden Bergstr. 66 01069 Dresden Germany
- Max Planck Institute for Chemical Physics of Solids Nöthnitzer Str. 40 01187 Dresden Germany
| | - Ute Kaiser
- Electron Microscopy Group of Materials Science (EMMS) Central Facility for Electron Microscopy Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Inez M. Weidinger
- Electrochemistry Technische Universität Dresden Zellescher Weg 19 01069 Dresden Germany
| | - Stefan Kaskel
- Inorganic Chemistry Center I Technische Universität Dresden Bergstr. 66 01069 Dresden Germany
- IWS Dresden Winterbergstr. 28 01277 Dresden Germany
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27
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Khurana S, Hassan MS, Yadav P, Ghosh D, Sapra S. Impact of Bifunctional Ligands on Charge Transfer Kinetics in CsPbBr 3-CdSe/CdS/ZnS Nanohybrids. J Phys Chem Lett 2022; 13:2591-2599. [PMID: 35290065 DOI: 10.1021/acs.jpclett.2c00067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Mixed dimensional nanohybrids (MDNHs) between zero-dimensional (0D) perovskites and two-dimensional (2D) II-VI semiconductors hold great potential for photonic device applications. An in-depth study to understand the shuttling of charge carriers is carried out utilizing bifunctional ligands such as 4-aminothiophenol (4-ATP), p-aminobenzoic acid, and 6-amino-2-naphthoic acid in the synthesis of MDNHs of CsPbBr3 nanocrystals (NCs) and CdSe/CdS/ZnS core/shell/shell (CSS) nanoplatelets (NPLs). These MDNHs form donor-bridge-acceptor systems, where the electronic interaction is greatly influenced by the nature of ligands. The smaller size and stronger binding affinity of 4-ATP to CSS NPLs lead to a faster rate of charge transfer as compared to other linkers. Electronic structure calculations under the framework of density functional theory (DFT) confirms that in 4-ATP capped CSS NPLs, stronger electronic overlap occurs between CSS NPLs and 4-ATP at the valence band maxima (VBM). Furthermore, Poisson distribution modeling proposes that in 4-ATP linked MDNHs, the number of CSS NPLs around CsPbBr3 NCs is highest.
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Affiliation(s)
- Swati Khurana
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Md Samim Hassan
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Priyesh Yadav
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Dibyajyoti Ghosh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Sameer Sapra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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28
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Kapuria N, Patil NN, Ryan KM, Singh S. Two-dimensional copper based colloidal nanocrystals: synthesis and applications. NANOSCALE 2022; 14:2885-2914. [PMID: 35156983 DOI: 10.1039/d1nr06990j] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Two-dimensional (2D) semiconductor nanocrystals display unconventional physical and opto-electronic properties due to their ultrathin and unique electronic structures. Since the success of Cd-based photoemissive nanocrystals, the development of sustainable and low-cost nanocrystals with enhanced electronic and physical properties has become a central research theme. In this context, copper-based semiconductor 2D nanocrystals, the cost-effective and eco-friendly alternative, exhibit unique plasmonic resonance, transport properties, and high ionic conductivity beneficial for sensing, energy storage, conversion, and catalytic applications. This review summarizes recent progress in the colloidal synthesis, growth mechanisms, properties, and applications of 2D copper-based nanostructures with tunable compositions, dimensions, and crystal phases. We highlight the growth mechanisms concerning their shape evolution in two dimensions. We analyse the effectiveness of cation exchange as a tool to synthesize multinary nanocrystals. Based on the preparation of Cu-based chalcogenide and non-chalcogenide compositions, we discuss synthesis control achieved via colloidal approaches to allow dimension tunability, phase engineering, and plasmonic and thermoelectric property optimization. Furthermore, their potential in various applications of catalysis, energy storage, and sensing is reviewed. Finally, we address the current challenges associated with 2D Cu-based nanocrystal development and provide an outlook pertaining to unexplored research areas.
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Affiliation(s)
- Nilotpal Kapuria
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, Ireland.
| | - Niraj Nitish Patil
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, Ireland.
| | - Kevin M Ryan
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, Ireland.
| | - Shalini Singh
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, Ireland.
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29
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Segura Lecina O, Hope MA, Venkatesh A, Björgvinsdóttir S, Rossi K, Loiudice A, Emsley L, Buonsanti R. Colloidal-ALD-Grown Hybrid Shells Nucleate via a Ligand-Precursor Complex. J Am Chem Soc 2022; 144:3998-4008. [PMID: 35195415 DOI: 10.1021/jacs.1c12538] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Colloidal atomic layer deposition (c-ALD) enables the growth of hybrid organic-inorganic oxide shells with tunable thickness at the nanometer scale around ligand-functionalized inorganic nanoparticles (NPs). This recently developed method has demonstrated improved stability of NPs and of their dispersions, a key requirement for their application. Nevertheless, the mechanism by which the inorganic shells form is still unknown, as is the nature of multiple complex interfaces between the NPs, the organic ligands functionalizing the surface, and the shell. Here, we demonstrate that carboxylate ligands are the key element that enables the synthesis of these core-shell structures. Dynamic nuclear polarization surface-enhanced nuclear magnetic resonance spectroscopy (DNP SENS) in combination with density functional theory (DFT) structure calculations shows that the addition of the aluminum organometallic precursor forms a ligand-precursor complex that interacts with the NP surface. This ligand-precursor complex is the first step for the nucleation of the shell and enables its further growth.
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Affiliation(s)
- Ona Segura Lecina
- Laboratory of Nanochemistry for Energy, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1950 Sion, Switzerland
| | - Michael A Hope
- Laboratory of Magnetic Resonance, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Amrit Venkatesh
- Laboratory of Magnetic Resonance, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Snædís Björgvinsdóttir
- Laboratory of Magnetic Resonance, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Kevin Rossi
- Laboratory of Nanochemistry for Energy, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1950 Sion, Switzerland
| | - Anna Loiudice
- Laboratory of Nanochemistry for Energy, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1950 Sion, Switzerland
| | - Lyndon Emsley
- Laboratory of Magnetic Resonance, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Raffaella Buonsanti
- Laboratory of Nanochemistry for Energy, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1950 Sion, Switzerland
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30
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Salzmann B, Wit JD, Li C, Arenas-Esteban D, Bals S, Meijerink A, Vanmaekelbergh D. Two-Dimensional CdSe-PbSe Heterostructures and PbSe Nanoplatelets: Formation, Atomic Structure, and Optical Properties. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:1513-1522. [PMID: 35116087 PMCID: PMC8802322 DOI: 10.1021/acs.jpcc.1c09412] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/30/2021] [Indexed: 06/12/2023]
Abstract
Cation exchange enables the preparation of nanocrystals (NCs), which are not reachable by direct synthesis methods. In this work, we applied Pb2+-for-Cd2+ cation exchange on CdSe nanoplatelets (NPLs) to prepare two-dimensional CdSe-PbSe heterostructures and PbSe NPLs. Lowering the reaction temperature slowed down the rate of cation exchange, making it possible to characterize the intermediary NCs ex situ with atomically resolved high-angle annular dark-field scanning transmission electron microscopy and optical spectroscopy. We observe that the Pb2+-for-Cd2+ cation exchange starts from the vertices of the NPLs and grows into the zinc blende CdSe (zb-CdSe) lattice as a rock salt PbSe phase (rs-PbSe), while the anion (selenium) sublattice is being preserved. In agreement with previous works on CdTe-PbTe films, the interfaces between zb-CdSe and rs-PbSe consist of shared {001} and {011} planes. The final PbSe NPLs are highly crystalline and contain protrusions at the edges, which are slightly rotated, indicating an atomic reconfiguration of material. The growth of PbSe domains into CdSe NPLs could also be monitored by the emission peak shift as a function of the exchange time. Temperature-dependent emission measurements confirm a size-dependent change of the band gap energy with temperature and reveal a strong influence of the anisotropic shape. Time-resolved photoluminescence measurements between 4 and 30 K show a dark-bright exciton-state splitting different from PbSe QDs with three-dimensional quantum confinement.
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Affiliation(s)
- Bastiaan
B.V. Salzmann
- Condensed
Matter & Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3508TA Utrecht, The Netherlands
| | - Jur de Wit
- Condensed
Matter & Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3508TA Utrecht, The Netherlands
| | - Chen Li
- EMAT
and Nanolab Centre of Excellence, Antwerp
University, 2020 Antwerp, Belgium
| | | | - Sara Bals
- EMAT
and Nanolab Centre of Excellence, Antwerp
University, 2020 Antwerp, Belgium
| | - Andries Meijerink
- Condensed
Matter & Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3508TA Utrecht, The Netherlands
| | - Daniel Vanmaekelbergh
- Condensed
Matter & Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, 3508TA Utrecht, The Netherlands
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31
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Tanghe I, Butkus J, Chen K, Tamming RR, Singh S, Ussembayev Y, Neyts K, van Thourhout D, Hodgkiss JM, Geiregat P. Broadband Optical Phase Modulation by Colloidal CdSe Quantum Wells. NANO LETTERS 2022; 22:58-64. [PMID: 34965360 DOI: 10.1021/acs.nanolett.1c03181] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Two-dimensional (2D) semiconductors are primed to realize a variety of photonic devices that rely on the transient properties of photogenerated charges, yet little is known on the change of the refractive index. The associated optical phase changes can be beneficial or undesired depending on the application, but require proper quantification. Measuring optical phase modulation of dilute 2D materials is, however, not trivial with common methods. Here, we demonstrate that 2D colloidal CdSe quantum wells, a useful model system, can modulate the phase of light across a broad spectrum using a femtosecond interferometry method. Next, we develop a toolbox to calculate the time-dependent refractive index of colloidal 2D materials from widely available transient absorption experiments using a modified effective medium algorithm. Our results show that the excitonic features of 2D materials result in broadband, ultrafast, and sizable phase modulation, even extending to the near infrared because of intraband transitions.
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Affiliation(s)
- Ivo Tanghe
- Photonics Research Group, Ghent University, Gent 9000, Belgium
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent 9000, Belgium
| | - Justinas Butkus
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin 9016, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6012, New Zealand
| | - Kai Chen
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Dunedin 9016, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6012, New Zealand
- Robinson Research Institute, Faculty of Engineering, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Ronnie R Tamming
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6012, New Zealand
- Robinson Research Institute, Faculty of Engineering, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Shalini Singh
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Yera Ussembayev
- Liquid Crystals and Photonics Research Group, Department of Electronics and Information Systems, Ghent University, Gent 9000, Belgium
| | - Kristiaan Neyts
- Liquid Crystals and Photonics Research Group, Department of Electronics and Information Systems, Ghent University, Gent 9000, Belgium
| | - Dries van Thourhout
- Photonics Research Group, Ghent University, Gent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent 9000, Belgium
| | - Justin M Hodgkiss
- School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6012, New Zealand
| | - Pieter Geiregat
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent 9000, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent 9000, Belgium
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32
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Guillemeney L, Lermusiaux L, Landaburu G, Wagnon B, Abécassis B. Curvature and self-assembly of semi-conducting nanoplatelets. Commun Chem 2022; 5:7. [PMID: 36697722 PMCID: PMC9814859 DOI: 10.1038/s42004-021-00621-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 12/21/2021] [Indexed: 01/28/2023] Open
Abstract
Semi-conducting nanoplatelets are two-dimensional nanoparticles whose thickness is in the nanometer range and controlled at the atomic level. They have come up as a new category of nanomaterial with promising optical properties due to the efficient confinement of the exciton in the thickness direction. In this perspective, we first describe the various conformations of these 2D nanoparticles which display a variety of bent and curved geometries and present experimental evidences linking their curvature to the ligand-induced surface stress. We then focus on the assembly of nanoplatelets into superlattices to harness the particularly efficient energy transfer between them, and discuss different approaches that allow for directional control and positioning in large scale assemblies. We emphasize on the fundamental aspects of the assembly at the colloidal scale in which ligand-induced forces and kinetic effects play a dominant role. Finally, we highlight the collective properties that can be studied when a fine control over the assembly of nanoplatelets is achieved.
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Affiliation(s)
- Lilian Guillemeney
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Laurent Lermusiaux
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Guillaume Landaburu
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Benoit Wagnon
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Benjamin Abécassis
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
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33
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Shen J, Luan C, Rowell N, Li Y, Zhang M, Chen X, Yu K. Size matters: Steric hindrance of precursor molecules controlling the evolution of CdSe magic-size clusters and quantum dots. NANO RESEARCH 2022; 15:8564-8572. [PMID: 35669506 PMCID: PMC9154029 DOI: 10.1007/s12274-022-4421-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/27/2022] [Accepted: 04/12/2022] [Indexed: 02/05/2023]
Abstract
Little is known about how to precisely promote the selective production of either colloidal semiconductor metal chalcogenide (ME), magic-size clusters (MSCs), or quantum dots (QDs). Recently, a two-pathway model has been proposed to comprehend their evolution; here, we reveal for the first time that the size of precursors plays a decisive role in the selected evolution pathway of MSCs and QDs. With the reaction of cadmium myristate (Cd(MA)2) and tri-n-octylphosphine selenide (SeTOP) in 1-octadecene (ODE) as a model system, the size of Cd precursors was manipulated by the steric hindrance of carboxylic acid (RCOOH) additive. Without RCOOH, the reaction produced both CdSe MSCs and QDs (from 100 to 240 °C). With RCOOH, the reaction produced MSCs or QDs when R was small (such as CH3-) or large (such as C6H5-), respectively. According to the two-pathway model, the selective evolution is attributed to the promotion and suppression of the self-assembly of Cd and Se precursors, respectively. We propose that the addition of carboxylic acid may occur ligand exchange with Cd(MA)2, causing the different sizes of Cd precursor. The results suggest that the size of Cd precursors regulates the self-assemble behavior of the precursors, which dictates the directed evolution of either MSCs or QDs. The present findings bring insights into the two-pathway model, as the size of M and E precursors determine the evolution pathways of MSCs or QDs, the understanding of which is of great fundamental significance toward mechanism-enabled design and predictive synthesis of functional nanomaterials. Electronic Supplementary Material Supplementary material (additional optical absorption spectra, TEM, NMR, FT-IR, and XRD) is available in the online version of this article at 10.1007/s12274-022-4421-4.
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Affiliation(s)
- Juan Shen
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, 610065 China
| | - Chaoran Luan
- Laboratory of Ethnopharmacology, Tissue-orientated Property of Chinese Medicine Key Laboratory of Sichuan Province, West China School of Medicine, West China Hospital, Sichuan University, Chengdu, 610065 China
| | - Nelson Rowell
- Metrology Research Centre, National Research Council Canada, Ottawa, Ontario K1A 0R6 Canada
| | - Yang Li
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, 610065 China
| | - Meng Zhang
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, 610065 China
| | - Xiaoqin Chen
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, 610065 China
| | - Kui Yu
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, 610065 China
- Laboratory of Ethnopharmacology, Tissue-orientated Property of Chinese Medicine Key Laboratory of Sichuan Province, West China School of Medicine, West China Hospital, Sichuan University, Chengdu, 610065 China
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, 610065 China
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34
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Zhu H, Li Z, Xu F, Qin Z, Sun R, Wang C, Lu S, Zhang Y, Fan H. Ni 3Se 4@CoSe 2 hetero-nanocrystals encapsulated into CNT-porous carbon interpenetrating frameworks for high-performance sodium ion battery. J Colloid Interface Sci 2021; 611:718-725. [PMID: 34876265 DOI: 10.1016/j.jcis.2021.11.175] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/26/2021] [Accepted: 11/27/2021] [Indexed: 10/19/2022]
Abstract
Core-shell structured Ni-ZIF-67@ZIF-8 derived bimetal selenides encapsulating into a 3D interpenetrating dual-carbon framework (Ni3Se4@CoSe2@C/CNTs) have been designed and prepared via carbonization and subsequent selenization processes. In this hierarchical structure, Ni3Se4@CoSe2 nanocrystals were uniformly dispersed into the 3D carbon frameworkstructure/carbon nanotubes networks, which greatly enhanced the electronic conductivity and further enabled ultrafast Na-ion diffusion kinetics. When used as anode materials of sodium ion battery (SIB), The Ni3Se4@CoSe2@C/CNTs electrode delivered the excellent rate capability of 206 mA h g-1 at 3 A g-1 and marvelous cyclic stability with capacity retention of 243 mA h g-1 after 600 cycles at 1 A g-1. This research provides a new way to prepare bimetallic selenide derived from MOF precursor with amazing heterostructure as the advanced anode materials for SIBs.
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Affiliation(s)
- Hangyi Zhu
- College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, PR China
| | - Zhiyong Li
- College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, PR China
| | - Feng Xu
- College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, PR China; School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, China
| | - Zhaoxia Qin
- College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, PR China; School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, China
| | - Rui Sun
- College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, PR China; School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, China
| | - Caihong Wang
- College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, PR China
| | - Shengjun Lu
- College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, PR China.
| | - Yufei Zhang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China.
| | - Haosen Fan
- School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, China.
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35
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Zhang Z, Thung YT, Wang L, Chen X, Ding L, Fan W, Sun H. Surface Depletion Effects in Bromide-Ligated Colloidal Cadmium Selenide Nanoplatelets: Toward Efficient Emission at High Temperature. J Phys Chem Lett 2021; 12:9086-9093. [PMID: 34519516 DOI: 10.1021/acs.jpclett.1c02623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The colloidal semiconductor nanoplatelet (NPL) with broad ligand-semiconductor interface is an ideal system for surface science investigation, but the study regarding depletion effects in NPLs remains lacking. Herein we explore such effects in colloidal CdSe NPLs through Br ligation. Apart from improved brightness and red-shifted optical features, we also experimentally observed abnormal negative thermal quenching phenomena in bromide-ligated CdSe NPLs over 200 K under a cryogenic environment and up to 383 K under an ambient environment, which was absent in pristine NPLs. We speculate that the surface depletion effect shall account for these anomalous phenomena due to the susceptibility of the surface depletion region on photoexcited carrier concentration and surface condition. The existence of the depletion layer in NPLs is also validated quantitatively with k·p simulation. Besides offering an alternative explanation on the red-shifted optical properties of CdSe NPLs by Br-ligation, our findings pave the new route toward solution-processed NPLs-based optoelectronics with boosted thermal resistance.
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Affiliation(s)
- Zitong Zhang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Yi Tian Thung
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Lin Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai 200072, China
| | - Xiaoxuan Chen
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Lu Ding
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), Singapore 138634, Singapore
| | - Weijun Fan
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Handong Sun
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
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36
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Nguyen KA, Pachter R, Day PN. Theoretical analysis of structures and electronic spectra of molecular colloidal cadmium sulfide clusters and nanoplatelets. J Chem Phys 2021; 155:094302. [PMID: 34496584 DOI: 10.1063/5.0057089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In the present study, we systematically examine structures and absorption spectra for CdS nanoplatelets (NPLs) with thicknesses of two and three monolayers (2 MLs and 3 MLs) and extended lateral dimensions. These nanoplatelet model systems, passivated with formate and acetate ligands, are used to analyze the effects of quantum confinement in the lateral dimension within an extended monolayer and the effects of thickness when changing from two to three monolayers. Based on the computed cubic structures using density functional theory (DFT), we found good agreement between observed and time-dependent DFT-calculated spectra, revealing little ligand participation to influence the color and intensity of low-energy absorption bands as the structures are laterally extended to eight and seven monolayers for 2-ML and 3-ML systems, respectively. The spectral redshift for 3-ML CdS NPLs is attributed to the electron delocalization due to expansion of the nanoplatelet in the lateral and vertical directions.
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Affiliation(s)
- Kiet A Nguyen
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433, USA
| | - Ruth Pachter
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433, USA
| | - Paul N Day
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433, USA
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37
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Stelmakh A, Aebli M, Baumketner A, Kovalenko MV. On the Mechanism of Alkylammonium Ligands Binding to the Surface of CsPbBr 3 Nanocrystals. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2021; 33:5962-5973. [PMID: 34393361 PMCID: PMC8359008 DOI: 10.1021/acs.chemmater.1c01081] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/08/2021] [Indexed: 05/20/2023]
Abstract
CsPbBr3 nanocrystals (NCs) suffer from instabilities caused by the dynamic and labile nature of both the inorganic core and the organic-inorganic interface. Surface ligand engineering thus remains an imminent research topic. In this study, classical molecular dynamics simulations with an explicit solvent are used to gain insights into the inherent binding properties of three different alkylammonium ligands-primary dodecylammonium (DA), secondary didodecylammonium (DDA), and quaternary dimethyldi- dodecylammonium (DMDDA). Our simulations uncover three main factors that govern the effective ligand-substrate interactions: (i) the ability of the head-group to penetrate into the binding pocket, (ii) the strength of head-group interactions with the polar solvent, and (iii) the higher barrier for ligand adsorption/desorption in the case of multiple alkyl chains. The interplay between these factors causes the following order of the binding free energies: DDA < DA ≈ DMDDA, while surface capping with DDA and DMDDA ligands is additionally stabilized by the kinetic barrier. These findings are in agreement with previous experimental observations and with the results of presented ligand-exchange experiments, wherein DDA is found to loosely bind to the CsPbBr3 surface, while DMDDA capping is more stable than capping with the primary oleylammonium ligand. The presented mechanistic understanding of the ligand-NC interactions will aid in the design of cationic ligands that make perovskite NC surfaces more robust.
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Affiliation(s)
- Andriy Stelmakh
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa—Swiss
Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Marcel Aebli
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa—Swiss
Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - Andrij Baumketner
- Institute
for Condensed Matter Physics, NAS of Ukraine, 1 Svientsitsky, Lviv 79011, Ukraine
| | - Maksym V. Kovalenko
- Laboratory
of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Laboratory
for Thin Films and Photovoltaics, Empa—Swiss
Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
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38
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Chen Y, Dorn RW, Hanrahan MP, Wei L, Blome-Fernández R, Medina-Gonzalez AM, Adamson MAS, Flintgruber AH, Vela J, Rossini AJ. Revealing the Surface Structure of CdSe Nanocrystals by Dynamic Nuclear Polarization-Enhanced 77Se and 113Cd Solid-State NMR Spectroscopy. J Am Chem Soc 2021; 143:8747-8760. [PMID: 34085812 DOI: 10.1021/jacs.1c03162] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Dynamic nuclear polarization (DNP) solid-state NMR (SSNMR) spectroscopy was used to obtain detailed surface structures of zinc blende CdSe nanocrystals (NCs) with plate or spheroidal morphologies which are capped by carboxylic acid ligands. 1D 113Cd and 77Se cross-polarization magic angle spinning (CPMAS) NMR spectra revealed distinct signals from Cd and Se atoms on the surface of the NCs, and those residing in bulk-like environments, below the surface. 113Cd cross-polarization magic-angle-turning (CP-MAT) experiments identified CdSe3O, CdSe2O2, and CdSeO3 Cd coordination environments on the surface of the NCs, where the oxygen atoms are presumably from coordinated carboxylate ligands. The sensitivity gain from DNP enabled natural isotopic abundance 2D homonuclear 113Cd-113Cd and 77Se-77Se and heteronuclear 113Cd-77Se scalar correlation solid-state NMR experiments which revealed the connectivity of the Cd and Se atoms. Importantly, 77Se{113Cd} scalar heteronuclear multiple quantum coherence (J-HMQC) experiments were used to selectively measure one-bond 77Se-113Cd scalar coupling constants (1J(77Se, 113Cd)). With knowledge of 1J(77Se, 113Cd), heteronuclear 77Se{113Cd} spin echo (J-resolved) NMR experiments were used to determine the number of Cd atoms bonded to Se atoms and vice versa. The J-resolved experiments directly confirmed that major Cd and Se surface species have CdSe2O2 and SeCd4 stoichiometries, respectively. Considering the crystal structure of zinc blende CdSe and the similarity of the solid-state NMR data for the platelets and spheroids, we conclude that the surface of the spheroidal CdSe NCs is primarily composed of {100} facets. The methods outlined here will generally be applicable to obtain detailed surface structures of various main group semiconductor nanoparticles.
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Affiliation(s)
- Yunhua Chen
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Rick W Dorn
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Michael P Hanrahan
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Lin Wei
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | | | | | - Marquix A S Adamson
- Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Anne H Flintgruber
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States
| | - Javier Vela
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Aaron J Rossini
- U.S. Department of Energy Ames Laboratory, Ames, Iowa 50011, United States.,Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
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39
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Geiregat P, Rodá C, Tanghe I, Singh S, Di Giacomo A, Lebrun D, Grimaldi G, Maes J, Van Thourhout D, Moreels I, Houtepen AJ, Hens Z. Localization-limited exciton oscillator strength in colloidal CdSe nanoplatelets revealed by the optically induced stark effect. LIGHT, SCIENCE & APPLICATIONS 2021; 10:112. [PMID: 34054127 PMCID: PMC8165098 DOI: 10.1038/s41377-021-00548-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/21/2021] [Accepted: 04/28/2021] [Indexed: 05/04/2023]
Abstract
2D materials are considered for applications that require strong light-matter interaction because of the apparently giant oscillator strength of the exciton transitions in the absorbance spectrum. Nevertheless, the effective oscillator strengths of these transitions have been scarcely reported, nor is there a consistent interpretation of the obtained values. Here, we analyse the transition dipole moment and the ensuing oscillator strength of the exciton transition in 2D CdSe nanoplatelets by means of the optically induced Stark effect (OSE). Intriguingly, we find that the exciton absorption line reacts to a high intensity optical field as a transition with an oscillator strength FStark that is 50 times smaller than expected based on the linear absorption coefficient. We propose that the pronounced exciton absorption line should be seen as the sum of multiple, low oscillator strength transitions, rather than a single high oscillator strength one, a feat we assign to strong exciton center-of-mass localization. Within the quantum mechanical description of excitons, this 50-fold difference between both oscillator strengths corresponds to the ratio between the coherence area of the exciton's center of mass and the total area, which yields a coherence area of a mere 6.1 nm2. Since we find that the coherence area increases with reducing temperature, we conclude that thermal effects, related to lattice vibrations, contribute to exciton localization. In further support of this localization model, we show that FStark is independent of the nanoplatelet area, correctly predicts the radiative lifetime, and lines up for strongly confined quantum dot systems.
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Affiliation(s)
- Pieter Geiregat
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent, Belgium.
- Center for Nano and Biophotonics, Ghent University, Gent, Belgium.
| | - Carmelita Rodá
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent, Belgium
| | - Ivo Tanghe
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent, Belgium
- Photonics Research Group, Ghent University, Gent, Belgium
| | - Shalini Singh
- Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick, Ireland
| | - Alessio Di Giacomo
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent, Belgium
| | - Delphine Lebrun
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent, Belgium
| | - Gianluca Grimaldi
- Center for Nanophotonics, NWO-Institute AMOLF, Science Park 104, 1098 XG, Amsterdam, The Netherlands
| | - Jorick Maes
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent, Belgium
| | - Dries Van Thourhout
- Center for Nano and Biophotonics, Ghent University, Gent, Belgium
- Photonics Research Group, Ghent University, Gent, Belgium
| | - Iwan Moreels
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent, Belgium
| | - Arjan J Houtepen
- Opto-Electronic Materials Section, Department of Chemical Engineering, Delft University, Delft, The Netherlands
| | - Zeger Hens
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, Gent, Belgium
- Center for Nano and Biophotonics, Ghent University, Gent, Belgium
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40
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Martinet Q, Baronnier J, Girard A, Albaret T, Saviot L, Mermet A, Abecassis B, Margueritat J, Mahler B. Ligand-dependent nano-mechanical properties of CdSe nanoplatelets: calibrating nanobalances for ligand affinity monitoring. NANOSCALE 2021; 13:8639-8647. [PMID: 33942037 DOI: 10.1039/d1nr00270h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The influence of ligands on the low frequency vibration of cadmium selenide colloidal nanoplatelets of different thicknesses is investigated using resonant low frequency Raman scattering. The strong vibration frequency shifts induced by ligand modifications as well as sharp spectral linewidths make low frequency Raman scattering a tool of choice to follow ligand exchange as well as the nano-mechanical properties of the NPLs, as evidenced by a carboxylate to thiolate exchange study. Apart from their molecular weight, the nature of the ligands, such as the sulfur to metal bond of thiols, induces a modification of the NPLs as a whole, increasing the thickness by one monolayer. Moreover, as the weight of the ligands increases, the discrepancy between the mass-load model and the experimental measurements increase. These effects are all the more important when the number of layers is small and can only be explained by a modification of the longitudinal sound velocity. This modification takes its origin in a change of the lattice structure of the NPLs, that reflects on their elastic properties. These nanobalances are finally used to characterize ligand affinity with the surface using binary thiol mixtures, illustrating the potential of low frequency Raman scattering to finely characterize nanocrystal surfaces.
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Affiliation(s)
- Quentin Martinet
- Institut Lumière Matière Université de Lyon, Université Claude Bernard Lyon 1, UMR CNRS 5306, F-69622 Villeurbanne, France.
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41
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Hinterding SM, Salzmann BBV, Vonk SJW, Vanmaekelbergh D, Weckhuysen BM, Hutter EM, Rabouw FT. Single Trap States in Single CdSe Nanoplatelets. ACS NANO 2021; 15:7216-7225. [PMID: 33759503 PMCID: PMC8155320 DOI: 10.1021/acsnano.1c00481] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Trap states can strongly affect semiconductor nanocrystals, by quenching, delaying, and spectrally shifting the photoluminescence (PL). Trap states have proven elusive and difficult to study in detail at the ensemble level, let alone in the single-trap regime. CdSe nanoplatelets (NPLs) exhibit significant fractions of long-lived "delayed emission" and near-infrared "trap emission". We use these two spectroscopic handles to study trap states at the ensemble and the single-particle level. We find that reversible hole trapping leads to both delayed and trap PL, involving the same trap states. At the single-particle level, reversible trapping induces exponential delayed PL and trap PL, with lifetimes ranging from 40 to 1300 ns. In contrast with exciton PL, single-trap PL is broad and shows spectral diffusion and strictly single-photon emission. Our results highlight the large inhomogeneity of trap states, even at the single-particle level.
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Affiliation(s)
- Stijn
O. M. Hinterding
- Soft
Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
| | - Bastiaan B. V. Salzmann
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
| | - Sander J. W. Vonk
- Soft
Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
| | - Daniel Vanmaekelbergh
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
| | - Bert M. Weckhuysen
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
| | - Eline M. Hutter
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
| | - Freddy T. Rabouw
- Soft
Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
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42
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Prins PT, Montanarella F, Dümbgen K, Justo Y, van der Bok JC, Hinterding SOM, Geuchies JJ, Maes J, De Nolf K, Deelen S, Meijer H, Zinn T, Petukhov AV, Rabouw FT, De Mello Donega C, Vanmaekelbergh D, Hens Z. Extended Nucleation and Superfocusing in Colloidal Semiconductor Nanocrystal Synthesis. NANO LETTERS 2021; 21:2487-2496. [PMID: 33661650 DOI: 10.1021/acs.nanolett.0c04813] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Hot-injection synthesis is renowned for producing semiconductor nanocolloids with superb size dispersions. Burst nucleation and diffusion-controlled size focusing during growth have been invoked to rationalize this characteristic yet experimental evidence supporting the pertinence of these concepts is scant. By monitoring a CdSe synthesis in-situ with X-ray scattering, we find that nucleation is an extended event that coincides with growth during 15-20% of the reaction time. Moreover, we show that size focusing outpaces predictions of diffusion-limited growth. This observation indicates that nanocrystal growth is dictated by the surface reactivity, which drops sharply for larger nanocrystals. Kinetic reaction simulations confirm that this so-called superfocusing can lengthen the nucleation period and promote size focusing. The finding that narrow size dispersions can emerge from the counteracting effects of extended nucleation and reaction-limited size focusing ushers in an evidence-based perspective that turns hot injection into a rational scheme to produce monodisperse semiconductor nanocolloids.
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Affiliation(s)
| | | | - Kim Dümbgen
- Physics and Chemistry of Nanostructures, Ghent University, B-9000 Gent, Belgium
| | - Yolanda Justo
- Physics and Chemistry of Nanostructures, Ghent University, B-9000 Gent, Belgium
| | | | | | | | - Jorick Maes
- Physics and Chemistry of Nanostructures, Ghent University, B-9000 Gent, Belgium
| | - Kim De Nolf
- Physics and Chemistry of Nanostructures, Ghent University, B-9000 Gent, Belgium
| | | | | | | | - Andrei V Petukhov
- Laboratory of Physical Chemistry, Eindhoven University of Technology, 5612 AZ Eindhoven, The Netherlands
| | | | | | | | - Zeger Hens
- Physics and Chemistry of Nanostructures, Ghent University, B-9000 Gent, Belgium
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43
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Peric N, Lambert Y, Singh S, Khan AH, Franchina Vergel NA, Deresmes D, Berthe M, Hens Z, Moreels I, Delerue C, Grandidier B, Biadala L. Van Hove Singularities and Trap States in Two-Dimensional CdSe Nanoplatelets. NANO LETTERS 2021; 21:1702-1708. [PMID: 33544602 DOI: 10.1021/acs.nanolett.0c04509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Semiconductor nanoplatelets, which offer a compelling combination of the flatness of two-dimensional semiconductors and the inherent richness brought about by colloidal nanostructure synthesis, form an ideal and general testbed to investigate fundamental physical effects related to the dimensionality of semiconductors. With low temperature scanning tunnelling spectroscopy and tight binding calculations, we investigate the conduction band density of states of individual CdSe nanoplatelets. We find an occurrence of peaks instead of the typical steplike function associated with a quantum well, that rule out a free in-plane electron motion, in agreement with the theoretical density of states. This finding, along with the detection of deep trap states located on the edge facets, which also restrict the electron motion, provides a detailed picture of the actual lateral confinement in quantum wells with finite length and width.
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Affiliation(s)
- Nemanja Peric
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Yannick Lambert
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Shalini Singh
- Physics and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Ali Hossain Khan
- Physics and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Nathali Alexandra Franchina Vergel
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Dominique Deresmes
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Maxime Berthe
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Zeger Hens
- Physics and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Iwan Moreels
- Physics and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Christophe Delerue
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Bruno Grandidier
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Louis Biadala
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
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44
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Moghaddam N, Dabard C, Dufour M, Po H, Xu X, Pons T, Lhuillier E, Ithurria S. Surface Modification of CdE (E: S, Se, and Te) Nanoplatelets to Reach Thicker Nanoplatelets and Homostructures with Confinement-Induced Intraparticle Type I Energy Level Alignment. J Am Chem Soc 2021; 143:1863-1872. [PMID: 33471504 DOI: 10.1021/jacs.0c10336] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Two-dimensional II-VI semiconductor nanoplatelets (NPLs) present exceptionally narrow optical features due to their thickness defined at the atomic scale. Because thickness drives the band-edge energy, its control is of paramount importance. Here, we demonstrate that native carboxylate ligands can be replaced by halides that partially dissolve cadmium chalcogenide NPLs at the edges. The released monomers then recrystallize on the wide top and bottom facets, leading to an increase in NPL thickness. This dissolution/recrystallization method is used to increase NPL thickness to 9 ML while using 3 ML NPLs as the starting material. We also demonstrate that this method is not limited to CdSe and can be extended to CdS and CdTe to grow thick NPLs. When the metal halide precursor is introduced with a chalcogenide precursor on the NPLs, CdSe/CdSe, CdTe/CdTe, and CdSe/CdTe core/shell homo- and heterostructures are achieved. Finally, when an incomplete layer is grown, NPLs with steps are synthesized. These stress-free homostructures are comparable to type I heterostructures, leading to recombination of the exciton in the thicker area of the NPLs. Following the growth of core/crown and core/shell NPLs, it affords a new degree of freedom for the growth of structured NPLs with designed band engineering, which has so far been only achievable for heteromaterial nanostructures.
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Affiliation(s)
- Nicolas Moghaddam
- CNRS, Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université UPMC Univ Paris 06, 10 rue Vauquelin, 75005 Paris, France
| | - Corentin Dabard
- CNRS, Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université UPMC Univ Paris 06, 10 rue Vauquelin, 75005 Paris, France.,CNRS, Institut des NanoSciences de Paris, INSP, Sorbonne Université, F-75005 Paris, France
| | - Marion Dufour
- CNRS, Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université UPMC Univ Paris 06, 10 rue Vauquelin, 75005 Paris, France
| | - Hong Po
- CNRS, Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université UPMC Univ Paris 06, 10 rue Vauquelin, 75005 Paris, France
| | - Xiangzhen Xu
- CNRS, Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université UPMC Univ Paris 06, 10 rue Vauquelin, 75005 Paris, France
| | - Thomas Pons
- CNRS, Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université UPMC Univ Paris 06, 10 rue Vauquelin, 75005 Paris, France
| | - Emmanuel Lhuillier
- CNRS, Institut des NanoSciences de Paris, INSP, Sorbonne Université, F-75005 Paris, France
| | - Sandrine Ithurria
- CNRS, Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université UPMC Univ Paris 06, 10 rue Vauquelin, 75005 Paris, France
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45
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Steiner AM, Lissel F, Fery A, Lauth J, Scheele M. Perspektiven gekoppelter organisch‐anorganischer Nanostrukturen für Ladungs‐ und Energietransferanwendungen. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.201916402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Anja Maria Steiner
- Institut Physikalische Chemie und Physik der Polymere Leibniz-Institut für Polymerforschung Hohe Str. 6 01069 Dresden Deutschland
| | - Franziska Lissel
- Institut Makromolekulare Chemie Leibniz-Institut für Polymerforschung Hohe Str. 6 01069 Dresden Deutschland
- Technische Universität Dresden Mommsenstr. 4 01064 Dresden Deutschland
| | - Andreas Fery
- Institut Physikalische Chemie und Physik der Polymere Leibniz-Institut für Polymerforschung Hohe Str. 6 01069 Dresden Deutschland
- Technische Universität Dresden Mommsenstr. 4 01064 Dresden Deutschland
| | - Jannika Lauth
- Leibniz-Universität Hannover Institut für Physikalische Chemie und Elektrochemie Callinstr. 3A 30167 Hannover Deutschland
| | - Marcus Scheele
- Eberhard-Karls-Universität Tübingen Institut für Physikalische und Theoretische Chemie Auf der Morgenstelle 18 72076 Tübingen Deutschland
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46
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Steiner AM, Lissel F, Fery A, Lauth J, Scheele M. Prospects of Coupled Organic-Inorganic Nanostructures for Charge and Energy Transfer Applications. Angew Chem Int Ed Engl 2021; 60:1152-1175. [PMID: 32173981 PMCID: PMC7821299 DOI: 10.1002/anie.201916402] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Indexed: 12/20/2022]
Abstract
We review the field of organic-inorganic nanocomposites with a focus on materials that exhibit a significant degree of electronic coupling across the hybrid interface. These nanocomposites undergo a variety of charge and energy transfer processes, enabling optoelectronic applications in devices which exploit singlet fission, triplet energy harvesting, photon upconversion or hot charge carrier transfer. We discuss the physical chemistry of the most common organic and inorganic components. Based on those we derive synthesis and assembly strategies and design criteria on material and device level with a focus on photovoltaics, spin memories or optical upconverters. We conclude that future research in the field should be directed towards an improved understanding of the binding motif and molecular orientation at the hybrid interface.
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Affiliation(s)
- Anja Maria Steiner
- Institute for Physical Chemistry and Polymer PhysicsLeibniz Institute of Polymer ResearchHohe Str. 601069DresdenGermany
| | - Franziska Lissel
- Institute of Macromolecular ChemistryLeibniz Institute of Polymer ResearchHohe Str. 601069DresdenGermany
- Technische Universität DresdenMommsenstr. 401064DresdenGermany
| | - Andreas Fery
- Institute for Physical Chemistry and Polymer PhysicsLeibniz Institute of Polymer ResearchHohe Str. 601069DresdenGermany
- Technische Universität DresdenMommsenstr. 401064DresdenGermany
| | - Jannika Lauth
- Leibniz Universität HannoverInstitute of Physical Chemistry and ElectrochemistryCallinstr. 3A30167HannoverGermany
| | - Marcus Scheele
- Eberhard Karls-Universität TübingenInstitute of Physical and Theoretical ChemistryAuf der Morgenstelle 1872076TübingenGermany
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47
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Hartley CL, Kessler ML, Dempsey JL. Molecular-Level Insight into Semiconductor Nanocrystal Surfaces. J Am Chem Soc 2021; 143:1251-1266. [PMID: 33442974 DOI: 10.1021/jacs.0c10658] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Semiconductor nanocrystals exhibit attractive photophysical properties for use in a variety of applications. Advancing the efficiency of nanocrystal-based devices requires a deep understanding of the physical defects and electronic states that trap charge carriers. Many of these states reside at the nanocrystal surface, which acts as an interface between the semiconductor lattice and the molecular capping ligands. While a detailed structural and electronic understanding of the surface is required to optimize nanocrystal properties, these materials are at a technical disadvantage: unlike molecular structures, semiconductor nanocrystals lack a specific chemical formula and generally must be characterized as heterogeneous ensembles. Therefore, in order for the field to improve current nanocrystal-based technologies, a creative approach to gaining a "molecular-level" picture of nanocrystal surfaces is required. To this end, an expansive toolbox of experimental and computational techniques has emerged in recent years. In this Perspective, we critically evaluate the insight into surface structure and reactivity that can be gained from each of these techniques and demonstrate how their strategic combination is already advancing our molecular-level understanding of nanocrystal surface chemistry.
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Affiliation(s)
- Carolyn L Hartley
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, United States
| | - Melody L Kessler
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, United States
| | - Jillian L Dempsey
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, United States
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48
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Lei H, Wang Y, Liu S, Zhu M, Pu C, Lin S, Qin H, Peng X. Delocalized Surface Electronic States on Polar Facets of Semiconductor Nanocrystals. ACS NANO 2020; 14:16614-16623. [PMID: 33095559 DOI: 10.1021/acsnano.0c07176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Wurtzite CdSe@CdS dot@platelet nanocrystals with (001) and (00-1) polar facets as the basal planes and (100) family of nonpolar facets as the side planes are applied for studying surface defects on semiconductor nanocrystals. When they are terminated with cadmium ions coordinated with carboxylate ligands, a single set of absorption features and band-edge photoluminescence (PL) with near unity PL quantum yield and monoexponential PL decay dynamics (lifetime ∼28 ns) are observed. In addition to these spectral signatures, when the surface is converted to sulfur-terminated, a second set of sharp absorption features with decent extinction coefficients and a secondary band-edge PL with low PL quantum yield and long-lifetime (>78 ns) PL decay dynamics are reproducibly recorded. Photochemical analysis confirms that the secondary UV-vis and PL spectral features are quantitatively correlated with each other. Chemical analysis and X-ray photoelectron spectroscopy measurements confirm that such secondary spectral features are well correlated with the sulfide (such as -SH) and disulfide (such as -S-S-) surface sites of a basal plane, which likely form surface hole electronic states delocalized on the entire basal plane. Results suggest that, for studying surface defects on semiconductor nanocrystals, it is essential to prepare a nearly monodisperse surface structure in terms of facets and surface chemical bonding.
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Affiliation(s)
- Hairui Lei
- Center for Chemistry of Novel and High-Performance Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yonghong Wang
- Center for Chemistry of Novel and High-Performance Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Shaojie Liu
- Center for Chemistry of Novel and High-Performance Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Meiyi Zhu
- Center for Chemistry of Novel and High-Performance Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Chaodan Pu
- Center for Chemistry of Novel and High-Performance Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Shangxin Lin
- Center for Chemistry of Novel and High-Performance Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Haiyan Qin
- Center for Chemistry of Novel and High-Performance Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Xiaogang Peng
- Center for Chemistry of Novel and High-Performance Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
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49
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Skurlov I, Sokolova A, Galle T, Cherevkov S, Ushakova E, Baranov A, Lesnyak V, Fedorov A, Litvin A. Temperature-Dependent Photoluminescent Properties of PbSe Nanoplatelets. NANOMATERIALS 2020; 10:nano10122570. [PMID: 33371429 PMCID: PMC7767437 DOI: 10.3390/nano10122570] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/15/2020] [Accepted: 12/18/2020] [Indexed: 01/17/2023]
Abstract
Semiconductor colloidal nanoplatelets (NPLs) are a promising new class of nanostructures that can bring much impact on lightning technologies, light-emitting diodes (LED), and laser fabrication. Indeed, great progress has been made in optimizing the optical properties of the NPLs for the visible spectral range, which has already made the implementation of a number of effective devices on their basis possible. To date, state-of-the-art near-infrared (NIR)-emitting NPLs are significantly inferior to their visible-range counterparts, although it would be fair to say that they received significantly less research attention so far. In this study, we report a comprehensive analysis of steady-state and time-dependent photoluminescence (PL) properties of four monolayered (ML) PbSe NPLs. The PL measurements are performed in a temperature range of 78–300 K, and their results are compared to those obtained for CdSe NPLs and PbSe quantum dots (QDs). We show that multiple emissive states, both band-edge and trap-related, are responsible for the formation of the NPLs’ PL band. We demonstrate that the widening of the PL band is caused by the inhomogeneous broadening rather than homogeneous one, and analyze the possible contributions to PL broadening.
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Affiliation(s)
- Ivan Skurlov
- Center of Information Optical Technology, The Laboratory “Optics of Quantum Nanostructures”, ITMO University, 49 Kronverksky Pr., St. Petersburg 197101, Russia; (I.S.); (A.S.); (S.C.); (E.U.); (A.B.); (A.F.)
| | - Anastasiia Sokolova
- Center of Information Optical Technology, The Laboratory “Optics of Quantum Nanostructures”, ITMO University, 49 Kronverksky Pr., St. Petersburg 197101, Russia; (I.S.); (A.S.); (S.C.); (E.U.); (A.B.); (A.F.)
| | - Tom Galle
- Physical Chemistry, TU Dresden, Zellescher Weg 19, 01069 Dresden, Germany; (T.G.); (V.L.)
| | - Sergei Cherevkov
- Center of Information Optical Technology, The Laboratory “Optics of Quantum Nanostructures”, ITMO University, 49 Kronverksky Pr., St. Petersburg 197101, Russia; (I.S.); (A.S.); (S.C.); (E.U.); (A.B.); (A.F.)
| | - Elena Ushakova
- Center of Information Optical Technology, The Laboratory “Optics of Quantum Nanostructures”, ITMO University, 49 Kronverksky Pr., St. Petersburg 197101, Russia; (I.S.); (A.S.); (S.C.); (E.U.); (A.B.); (A.F.)
| | - Alexander Baranov
- Center of Information Optical Technology, The Laboratory “Optics of Quantum Nanostructures”, ITMO University, 49 Kronverksky Pr., St. Petersburg 197101, Russia; (I.S.); (A.S.); (S.C.); (E.U.); (A.B.); (A.F.)
| | - Vladimir Lesnyak
- Physical Chemistry, TU Dresden, Zellescher Weg 19, 01069 Dresden, Germany; (T.G.); (V.L.)
| | - Anatoly Fedorov
- Center of Information Optical Technology, The Laboratory “Optics of Quantum Nanostructures”, ITMO University, 49 Kronverksky Pr., St. Petersburg 197101, Russia; (I.S.); (A.S.); (S.C.); (E.U.); (A.B.); (A.F.)
| | - Aleksandr Litvin
- Center of Information Optical Technology, The Laboratory “Optics of Quantum Nanostructures”, ITMO University, 49 Kronverksky Pr., St. Petersburg 197101, Russia; (I.S.); (A.S.); (S.C.); (E.U.); (A.B.); (A.F.)
- Correspondence: ; Tel.: +7-950-0286240
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50
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Di Giacomo A, Rodà C, Khan AH, Moreels I. Colloidal Synthesis of Laterally Confined Blue-Emitting 3.5 Monolayer CdSe Nanoplatelets. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2020; 32:9260-9267. [PMID: 33191978 PMCID: PMC7659369 DOI: 10.1021/acs.chemmater.0c03066] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/09/2020] [Indexed: 05/03/2023]
Abstract
The typical synthesis protocol for blue-emitting CdSe nanoplatelets (NPLs) yields particles with extended lateral dimensions and large surface areas, resulting in NPLs with poor photoluminescence quantum efficiency. We have developed a synthesis protocol that achieves an improved control over the lateral size, by exploiting a series of long-chained carboxylate precursors that vary from cadmium octanoate (C8) to cadmium stearate (C18). The length of this metallic precursor is key to tune the width and aspect ratio of the final NPLs, and for the shorter chain lengths, the synthesis yield is improved. NPLs prepared with our procedure possess significantly enhanced photoluminescence quantum efficiencies, up to 30%. This is likely due to their reduced lateral dimensions, which also grant them good colloidal stability. As the NPL width can be tuned below the bulk exciton Bohr radius, the band edge blue-shifts, and we constructed a sizing curve relating the NPL absorption position and width. Further adjusting the synthesis protocol, we were able to obtain even thinner NPLs, emitting in the near-UV region, with a band-edge quantum efficiency of up to 11%. Results pave the way to stable and efficient light sources for applications such as blue and UV light-emitting devices and lasers.
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