1
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Pluta D, Kuper H, Graf RT, Wesemann C, Rusch P, Becker JA, Bigall NC. Optical properties of NIR photoluminescent PbS nanocrystal-based three-dimensional networks. NANOSCALE ADVANCES 2023; 5:5005-5014. [PMID: 37705785 PMCID: PMC10496766 DOI: 10.1039/d3na00404j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/25/2023] [Indexed: 09/15/2023]
Abstract
The assembly of nanocrystals (NCs) into three-dimensional network structures is a recently established strategy to produce macroscopic materials with nanoscopic properties. These networks can be formed by the controlled destabilization of NC colloids and subsequent supercritical drying to obtain NC-based aerogels. Even though this strategy has been used for many different semiconductor NCs, the emission of NC-based aerogels is limited to the ultraviolet and visible and no near-infrared (NIR) emitting NC-based aerogels have been investigated in literature until now. In the present work we have optimized a gelation route of NIR emitting PbS and PbS/CdS quantum dots (QDs) by means of a recently established gel formation method using trivalent ions to induce the network formation. Thereby, depending on the surface ligands and QDs used the resulting network structure is different. We propose, that the ligand affinity to the nanocrystal surface plays an essential role during network formation, which is supported by theoretical calculations. The optical properties were investigated with a focus on their steady-state and time resolved photoluminescence (PL). Unlike in PbS/CdS aerogels, the absorption of PbS aerogels and their PL shift strongly. For all aerogels the PL lifetimes are reduced in comparison to those of the building blocks with this reduction being especially pronounced in the PbS aerogels.
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Affiliation(s)
- Denis Pluta
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover Schneiderberg 39 30167 Hannover Germany
| | - Henning Kuper
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
| | - Rebecca T Graf
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover Schneiderberg 39 30167 Hannover Germany
| | - Christoph Wesemann
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
| | - Pascal Rusch
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover Schneiderberg 39 30167 Hannover Germany
| | - Joerg August Becker
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
| | - Nadja C Bigall
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover Callinstraße 3A 30167 Hannover Germany
- Laboratory of Nano and Quantum Engineering, Leibniz University Hannover Schneiderberg 39 30167 Hannover Germany
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2
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Chiang W, Stout A, Yanchik-Slade F, Li H, Terrando N, Nilsson BL, Gelbard HA, Krauss TD. Quantum Dot Biomimetic for SARS-CoV-2 to Interrogate Blood-Brain Barrier Damage Relevant to NeuroCOVID Brain Inflammation. ACS APPLIED NANO MATERIALS 2023; 6:15094-15107. [PMID: 37649833 PMCID: PMC10463222 DOI: 10.1021/acsanm.3c02719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 07/24/2023] [Indexed: 09/01/2023]
Abstract
Despite limited evidence for infection of SARS-CoV-2 in the central nervous system, cognitive impairment is a common complication reported in "recovered" COVID-19 patients. Identification of the origins of these neurological impairments is essential to inform therapeutic designs against them. However, such studies are limited, in part, by the current status of high-fidelity probes to visually investigate the effects of SARS-CoV-2 on the system of blood vessels and nerve cells in the brain, called the neurovascular unit. Here, we report that nanocrystal quantum dot micelles decorated with spike protein (COVID-QDs) are able to interrogate neurological damage due to SARS-CoV-2. In a transwell co-culture model of the neurovascular unit, exposure of brain endothelial cells to COVID-QDs elicited an inflammatory response in neurons and astrocytes without direct interaction with the COVID-QDs. These results provide compelling evidence of an inflammatory response without direct exposure to SARS-CoV-2-like nanoparticles. Additionally, we found that pretreatment with a neuro-protective molecule prevented endothelial cell damage resulting in substantial neurological protection. These results will accelerate studies into the mechanisms by which SARS-CoV-2 mediates neurologic dysfunction.
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Affiliation(s)
- Wesley Chiang
- Department
of Biochemistry and Biophysics, Center for Neurotherapeutics Discovery
and Department of Neurology, and Departments of Pediatrics, Neuroscience, and
Microbiology and Immunology, University
of Rochester Medical Center, Rochester, New York 14642, United States
| | - Angela Stout
- Department
of Biochemistry and Biophysics, Center for Neurotherapeutics Discovery
and Department of Neurology, and Departments of Pediatrics, Neuroscience, and
Microbiology and Immunology, University
of Rochester Medical Center, Rochester, New York 14642, United States
| | - Francine Yanchik-Slade
- Department of Chemistry and The Institute of Optics, University of Rochester, Rochester, New York 14627, United States
| | - Herman Li
- Department
of Biochemistry and Biophysics, Center for Neurotherapeutics Discovery
and Department of Neurology, and Departments of Pediatrics, Neuroscience, and
Microbiology and Immunology, University
of Rochester Medical Center, Rochester, New York 14642, United States
| | - Niccolò Terrando
- Department
of Anesthesiology, Duke University Medical
Center, Durham, North Carolina 27710, United States
| | - Bradley L. Nilsson
- Department of Chemistry and The Institute of Optics, University of Rochester, Rochester, New York 14627, United States
| | - Harris A. Gelbard
- Department
of Biochemistry and Biophysics, Center for Neurotherapeutics Discovery
and Department of Neurology, and Departments of Pediatrics, Neuroscience, and
Microbiology and Immunology, University
of Rochester Medical Center, Rochester, New York 14642, United States
| | - Todd D. Krauss
- Department of Chemistry and The Institute of Optics, University of Rochester, Rochester, New York 14627, United States
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3
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Lagos KJ, García D, Cuadrado CF, de Souza LM, Mezzacappo NF, da Silva AP, Inada N, Bagnato V, Romero MP. Carbon dots: Types, preparation, and their boosted antibacterial activity by photoactivation. Current status and future perspectives. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2023:e1887. [PMID: 37100045 DOI: 10.1002/wnan.1887] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 02/14/2023] [Accepted: 03/03/2023] [Indexed: 04/28/2023]
Abstract
Carbon dots (CDs) correspond to carbon-based materials (CBM) with sizes usually below 10 nm. These nanomaterials exhibit attractive properties such us low toxicity, good stability, and high conductivity, which have promoted their thorough study over the past two decades. The current review describes four types of CDs: carbon quantum dots (CQDs), graphene quantum dots (GQDs), carbon nanodots (CNDs), and carbonized polymers dots (CPDs), together with the state of the art of the main routes for their preparation, either by "top-down" or "bottom-up" approaches. Moreover, among the various usages of CDs within biomedicine, we have focused on their application as a novel class of broad-spectrum antibacterial agents, concretely, owing their photoactivation capability that triggers an enhanced antibacterial property. Our work presents the recent advances in this field addressing CDs, their composites and hybrids, applied as photosensitizers (PS), and photothermal agents (PA) within antibacterial strategies such as photodynamic therapy (PDT), photothermal therapy (PTT), and synchronic PDT/PTT. Furthermore, we discuss the prospects for the possible future development of large-scale preparation of CDs, and the potential for these nanomaterials to be employed in applications to combat other pathogens harmful to human health. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.
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Affiliation(s)
- Karina J Lagos
- Department of Materials, Escuela Politécnica Nacional (EPN), Quito, Ecuador
| | - David García
- Department of Materials, Escuela Politécnica Nacional (EPN), Quito, Ecuador
| | | | | | | | - Ana Paula da Silva
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, Brazil
| | - Natalia Inada
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, Brazil
| | - Vanderlei Bagnato
- São Carlos Institute of Physics, University of São Paulo (USP), São Carlos, Brazil
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4
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Shi R, Fang Q, Vasenko AS, Long R, Fang WH, Prezhdo OV. Structural Disorder in Higher-Temperature Phases Increases Charge Carrier Lifetimes in Metal Halide Perovskites. J Am Chem Soc 2022; 144:19137-19149. [PMID: 36206144 DOI: 10.1021/jacs.2c08627] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Solar cells and optoelectronic devices are exposed to heat that degrades performance. Therefore, elucidating temperature-dependent charge carrier dynamics is essential for device optimization. Charge carrier lifetimes decrease with temperature in conventional semiconductors. The opposite, anomalous trend is observed in some experiments performed with MAPbI3 (MA = CH3NH3+) and other metal halide perovskites. Using ab initio quantum dynamics simulation, we establish the atomic mechanisms responsible for nonradiative electron-hole recombination in orthorhombic-, tetragonal-, and cubic MAPbI3. We demonstrate that structural disorder arising from the phase transitions is as important as the disorder due to heating in the same phase. The carrier lifetimes grow both with increasing temperature in the same phase and upon transition to the higher-temperature phases. The increased lifetime is rationalized by structural disorder that induces partial charge localization, decreases nonadiabatic coupling, and shortens quantum coherence. Inelastic and elastic electron-vibrational interactions exhibit opposite dependence on temperature and phase. The partial disorder and localization arise from thermal motions of both the inorganic lattice and the organic cations and depend significantly on the phase. The structural deformations induced by thermal fluctuations and phase transitions are on the same order as deformations induced by defects, and hence, thermal disorder plays a very important role. Since charge localization increases carrier lifetimes but inhibits transport, an optimal regime maximizing carrier diffusion can be designed, depending on phase, temperature, material morphology, and device architecture. The atomistic mechanisms responsible for the enhanced carrier lifetimes at elevated temperatures provide guidelines for the design of improved solar energy and optoelectronic materials.
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Affiliation(s)
- Ran Shi
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | - Qiu Fang
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | | | - Run Long
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, College of Chemistry, Beijing Normal University, Beijing100875, People's Republic of China
| | - Oleg V Prezhdo
- Departments of Chemistry, and Physics and Astronomy, University of Southern California, Los Angeles, California90089, United States
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5
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Shi R, Vasenko AS, Long R, Prezhdo OV. Edge Influence on Charge Carrier Localization and Lifetime in CH 3NH 3PbBr 3 Perovskite: Ab Initio Quantum Dynamics Simulation. J Phys Chem Lett 2020; 11:9100-9109. [PMID: 33048554 DOI: 10.1021/acs.jpclett.0c02800] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The distribution of charge carriers in metal halide perovskites draws strong interest from the solar cell community, with experiments demonstrating that edges of various microstructures can improve material performance. This is rather surprising because edges and grain boundaries are often viewed as the main source of charge traps. We demonstrate by ab initio quantum dynamics simulations that edges of the CH3NH3PbBr3 perovskite create shallow trap states that mix well with the valence and conduction bands of the bulk and therefore support mobile charge carriers. Charges are steered to the edges energetically, facilitating dissociation of photo-generated excitons into free carriers. The edge-driven charge separation extends carrier lifetimes because of decreased overlap of the electron and hole wave functions, which leads to reduction of the nonadiabatic coupling responsible for nonradiative electron-hole recombination. Reduction of spatial symmetry near the edges activates additional vibrational modes that accelerate coherence loss within the electronic subsystem, further extending carrier lifetimes. Enhanced atomic motions at edges increase fluctuations of edge energy levels, enhancing mixing with band states and improving charge mobility. The simulations contribute to the atomistic understanding of the unusual properties of metal halide perovskites, generating the fundamental knowledge needed to design high-performance optoelectronic devices.
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Affiliation(s)
- Ran Shi
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Andrey S Vasenko
- National Research University Higher School of Economics, 101000 Moscow, Russia
- I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute, Russian Academy of Sciences, 119991 Moscow, Russia
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Oleg V Prezhdo
- Departments of Chemistry, and Physics and Astronomy, University of Southern California, Los Angeles, California 90089, United States
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6
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Influence of Surface Ligands on Charge-Carrier Trapping and Relaxation in Water-Soluble CdSe@CdS Nanorods. Catalysts 2020. [DOI: 10.3390/catal10101143] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In this study, the impact of the type of ligand at the surface of colloidal CdSe@CdS dot-in-rod nanostructures on the basic exciton relaxation and charge localization processes is closely examined. These systems have been introduced into the field of artificial photosynthesis as potent photosensitizers in assemblies for light driven hydrogen generation. Following photoinduced exciton generation, electrons can be transferred to catalytic reaction centers while holes localize into the CdSe seed, which can prevent charge recombination and lead to the formation of long-lived charge separation in assemblies containing catalytic reaction centers. These processes are in competition with trapping processes of charges at surface defect sites. The density and type of surface defects strongly depend on the type of ligand used. Here we report on a systematic steady-state and time-resolved spectroscopic investigation of the impact of the type of anchoring group (phosphine oxide, thiols, dithiols, amines) and the bulkiness of the ligand (alkyl chains vs. poly(ethylene glycol) (PEG)) to unravel trapping pathways and localization efficiencies. We show that the introduction of the widely used thiol ligands leads to an increase of hole traps at the surface compared to trioctylphosphine oxide (TOPO) capped rods, which prevent hole localization in the CdSe core. On the other hand, steric restrictions, e.g., in dithiolates or with bulky side chains (PEG), decrease the surface coverage, and increase the density of electron trap states, impacting the recombination dynamics at the ns timescale. The amines in poly(ethylene imine) (PEI) on the other hand can saturate and remove surface traps to a wide extent. Implications for catalysis are discussed.
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7
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Lystrom L, Tamukong P, Mihaylov D, Kilina S. Phonon-Driven Energy Relaxation in PbS/CdS and PbSe/CdSe Core/Shell Quantum Dots. J Phys Chem Lett 2020; 11:4269-4278. [PMID: 32354213 DOI: 10.1021/acs.jpclett.0c00845] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We study the impact of the chemical composition on phonon-mediated exciton relaxation in the core/shell quantum dots (QDs), with 1 nm core made of PbX and the monolayer shell made of CdX, where X = S and Se. For this, time-domain nonadiabatic molecular dynamics (NAMD) based on density functional theory (DFT) and surface hopping techniques are applied. Simulations reveal twice faster energy relaxation in PbS/CdS than PbSe/CdSe because of dominant couplings to higher-energy optical phonons in structures with sulfur anions. For both QDs, the long-living intermediate states associated with the core-shell interface govern the dynamics. Therefore, a simple exponential model is not appropriate, and the four-state irreversible kinetic model is suggested instead, predicting 0.9 and 0.5 ps relaxation rates in PbSe/CdSe and PbS/CdS QDs, respectively. Thus, 2 nm PdSe/CdSe QDs with a single monolayer shell exhibit the phonon-mediated relaxation time sufficient for carrier multiplications to outpace energy dissipation and benefit the solar conversion efficiency.
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Affiliation(s)
- Levi Lystrom
- Chemistry & Biochemistry Department, North Dakota State University, Fargo, North Dakota 58108, United States
| | - Patrick Tamukong
- School of Medicine & Health Sciences, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Deyan Mihaylov
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, United States
| | - Svetlana Kilina
- Chemistry & Biochemistry Department, North Dakota State University, Fargo, North Dakota 58108, United States
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8
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Simi N, Ison V. Synthesis and characterization of amine stabilized CdSe quantum dots. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.matpr.2019.12.158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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9
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Wang B, Liu L, Zhang Y, Deng Y, Dong A. A novel strategy for boosting the photoluminescence quantum efficiency of CdSe nanocrystals at room temperature. CHINESE CHEM LETT 2020. [DOI: 10.1016/j.cclet.2019.03.043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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10
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Nagakubo J, Nishihashi T, Mishima K, Yamashita K. First-principles approach to the first step of metal–phosphine bond formation to synthesize alloyed quantum dots using dissimilar metal precursors. Chem Phys 2020. [DOI: 10.1016/j.chemphys.2019.110512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Liu X, Zhang X, Li L, Xu J, Yu S, Gong X, Zhang J, Yin H. Stable Luminescence of CsPbBr 3/ nCdS Core/Shell Perovskite Quantum Dots with Al Self-Passivation Layer Modification. ACS APPLIED MATERIALS & INTERFACES 2019; 11:40923-40931. [PMID: 31588719 DOI: 10.1021/acsami.9b14967] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Perovskite quantum dots (PQDs) are among the most important luminescent semiconducting materials; however, they are unstable. Exposure to light, heat, and air can lead to irreversible degradation, which results in fluorescence quenching. Therefore, defects in PQDs significantly limit their practical application. Herein, we describe a simple method to enhance the photostability of CsPbBr3/nCdS QDs, which involves doping their shells with aluminum. The temperature-dependent photoluminescence (PL) of colloidal CsPbBr3/nCdS/Al2O3 QDs is investigated, and the thermal quenching of PL, blue shift of the optical band gap, and PL line width broadening are observed in each QD sample. Al2O3 layers on the CsPbBr3/nCdS QDs can effectively prevent photodegradation. Nonlinear, temperature-dependent exciton-phonon coupling and lattice dilation leads to radiative and nonradiative relaxation processes at temperatures ranging from 10 to 300 K; moreover, changes in the band gap and PL spectral line broadening are observed.
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Affiliation(s)
- Xin Liu
- School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology , Tianjin 300384 , China
| | - Xiaosong Zhang
- School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology , Tianjin 300384 , China
| | - Lan Li
- School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology , Tianjin 300384 , China
| | - Jianping Xu
- School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology , Tianjin 300384 , China
| | - Shuili Yu
- School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology , Tianjin 300384 , China
| | - Xiaokai Gong
- School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology , Tianjin 300384 , China
| | - Jiajia Zhang
- School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology , Tianjin 300384 , China
| | - Hao Yin
- School of Materials Science and Engineering, Institute of Material Physics, Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, and Tianjin Key Laboratory for Photoelectric Materials and Devices, and National Demonstration Center for Experimental Function Materials Education , Tianjin University of Technology , Tianjin 300384 , China
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12
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Zhang Z, Fang WH, Long R, Prezhdo OV. Exciton Dissociation and Suppressed Charge Recombination at 2D Perovskite Edges: Key Roles of Unsaturated Halide Bonds and Thermal Disorder. J Am Chem Soc 2019; 141:15557-15566. [DOI: 10.1021/jacs.9b06046] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Zhaosheng Zhang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People’s Republic of China
| | - Wei-Hai Fang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People’s Republic of China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, People’s Republic of China
| | - Oleg V. Prezhdo
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
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13
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Synthesis of CdSe on FTO-supported ZnO nanorods by SILAR and electrochemical methods and comparison of photoelectrochemical properties of FTO/ZnO/CdSe systems in aqueous S2−/Sn2− electrolyte. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.12.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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15
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Frenette LC, Krauss TD. Uncovering active precursors in colloidal quantum dot synthesis. Nat Commun 2017; 8:2082. [PMID: 29233976 PMCID: PMC5727186 DOI: 10.1038/s41467-017-01936-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 10/26/2017] [Indexed: 11/09/2022] Open
Abstract
Studies of the fundamental physics and chemistry of colloidal semiconductor nanocrystal quantum dots (QDs) have been central to the field for over 30 years. Although the photophysics of QDs has been intensely studied, much less is understood about the underlying chemical reaction mechanism leading to monomer formation and subsequent QD growth. Here we investigate the reaction mechanism behind CdSe QD synthesis, the most widely studied QD system. Remarkably, we find that it is not necessary for chemical precursors used in the most common synthetic methods to directly react to form QD monomers, but rather they can generate in situ the same highly reactive Cd and Se precursors that were used in some of the original II-VI QD syntheses decades ago, i.e., hydrogen chalcogenide gas and alkyl cadmium. Appreciating this surprising finding may allow for directed manipulation of these reactive intermediates, leading to more controlled syntheses with improved reproducibility. Little is understood about the chemical evolution of precursors to quantum dots. Here, the authors find that under the high temperature conditions typical of CdSe quantum dot synthesis, precursors decompose into highly reactive species in a critical first step before forming monomers and finally nanocrystals.
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Affiliation(s)
- Leah C Frenette
- Department of Chemistry, University of Rochester, Rochester, NY, 14627-0216, USA
| | - Todd D Krauss
- Department of Chemistry, University of Rochester, Rochester, NY, 14627-0216, USA. .,Institute of Optics, University of Rochester, Rochester, NY, 14627-0216, USA.
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16
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17
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Gray V, Xia P, Huang Z, Moses E, Fast A, Fishman DA, Vullev VI, Abrahamsson M, Moth-Poulsen K, Lee Tang M. CdS/ZnS core-shell nanocrystal photosensitizers for visible to UV upconversion. Chem Sci 2017; 8:5488-5496. [PMID: 28970929 PMCID: PMC5613741 DOI: 10.1039/c7sc01610g] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 05/30/2017] [Indexed: 12/29/2022] Open
Abstract
Herein we report the first example of nanocrystal (NC) sensitized triplet-triplet annihilation based photon upconversion from the visible to ultraviolet (vis-to-UV). Many photocatalyzed reactions, such as water splitting, require UV photons in order to function efficiently. Upconversion is one possible means of extending the usable range of photons into the visible. Vis-to-UV upconversion is achieved with CdS/ZnS core-shell NCs as the sensitizer and 2,5-diphenyloxazole (PPO) as annihilator and emitter. The ZnS shell was crucial in order to achieve any appreciable upconversion. From time resolved photoluminescence and transient absorption measurements we conclude that the ZnS shell affects the NC and triplet energy transfer (TET) from NC to PPO in two distinct ways. Upon ZnS growth the surface traps are passivated thus increasing the TET. The shell, however, also acts as a tunneling barrier for TET, reducing the efficiency. This leads to an optimal shell thickness where the upconversion quantum yield (Φ'UC) is maximized. Here the maximum Φ'UC was determined to be 5.2 ± 0.5% for 4 monolayers of ZnS shell on CdS NCs.
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Affiliation(s)
- Victor Gray
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , 412 96 Gothenburg , Sweden
| | - Pan Xia
- Materials Science & Engineering Program , University of California, Riverside , 900 University Ave. , Riverside , CA 92521 , USA
| | - Zhiyuan Huang
- Department of Chemistry , University of California, Riverside , 900 University Ave. , Riverside , CA 92521 , USA .
| | - Emily Moses
- Department of Chemistry , University of California, Riverside , 900 University Ave. , Riverside , CA 92521 , USA .
| | - Alexander Fast
- Department of Chemistry , University of California , Irvine , CA 92697 , USA
| | - Dmitry A Fishman
- Department of Chemistry , University of California , Irvine , CA 92697 , USA
| | - Valentine I Vullev
- Department of Chemistry , University of California, Riverside , 900 University Ave. , Riverside , CA 92521 , USA .
| | - Maria Abrahamsson
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , 412 96 Gothenburg , Sweden
| | - Kasper Moth-Poulsen
- Department of Chemistry and Chemical Engineering , Chalmers University of Technology , 412 96 Gothenburg , Sweden
| | - Ming Lee Tang
- Department of Chemistry , University of California, Riverside , 900 University Ave. , Riverside , CA 92521 , USA .
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Abbasi S, Molaei M, Karimipour M. CdSe and CdSe/CdS core–shell QDs: New approach for synthesis, investigating optical properties and application in pollutant degradation. LUMINESCENCE 2017; 32:1137-1144. [DOI: 10.1002/bio.3300] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 01/20/2017] [Accepted: 01/23/2017] [Indexed: 11/09/2022]
Affiliation(s)
- S. Abbasi
- Department of Physics, Faculty of Science Vali‐e‐Asr University Rafsanjan Iran
| | - M. Molaei
- Department of Physics, Faculty of Science Vali‐e‐Asr University Rafsanjan Iran
| | - M. Karimipour
- Department of Physics, Faculty of Science Vali‐e‐Asr University Rafsanjan Iran
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Long R, Prezhdo OV, Fang W. Nonadiabatic charge dynamics in novel solar cell materials. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2017. [DOI: 10.1002/wcms.1305] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education Beijing Normal University Beijing P.R. China
| | - Oleg V. Prezhdo
- Department of Chemistry University of Southern California Los Angeles CA USA
| | - Weihai Fang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education Beijing Normal University Beijing P.R. China
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