1
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Dziobek-Garrett R, Kempa TJ. Excitons at the interface of 2D TMDs and molecular semiconductors. J Chem Phys 2024; 160:200902. [PMID: 38804485 DOI: 10.1063/5.0206417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 05/02/2024] [Indexed: 05/29/2024] Open
Abstract
Van der Waals heterostructures (vdWHs) of vertically stacked two-dimensional (2D) atomic crystals have been used to elicit intriguing phenomena stemming from strong electronic correlations, magnetic textures, and interlayer excitons spawned at the heterointerface. However, vdWHs comprised of heterointerfaces between these 2D atomic crystal lattices and molecular assemblies are emerging as equally intriguing platforms supporting properties to be harnessed for photovoltaic energy conversion, photodetection, spin-selective charge injection, and quantum emission. In this perspective, we summarize recent research examining exciton dynamics in heterostructures between semiconducting 2D transition metal dichalcogenides and molecular organic semiconductors. We discuss methods for assembly of these heterostructures, the nature of interlayer or charge-transfer excitons at transition-metal dichalcogenide (TMD)-molecule interfaces, explicit exciton transfer between organics and TMDs, and other interfacial phenomena driven by the merger of these two material classes. We also suggest key new research directions extending the remit of these 2D atomic-molecular lattice heterointerfaces into the domains of condensed matter physics, quantum sensing, and energy conversion.
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Affiliation(s)
| | - Thomas J Kempa
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
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2
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Krumland J, Cocchi C. Ab Initio Modeling of Mixed-Dimensional Heterostructures: A Path Forward. J Phys Chem Lett 2024; 15:5350-5358. [PMID: 38728611 PMCID: PMC11129309 DOI: 10.1021/acs.jpclett.4c00803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/26/2024] [Accepted: 05/08/2024] [Indexed: 05/12/2024]
Abstract
Understanding the electronic structure of mixed-dimensional heterostructures is essential for maximizing their application potential. However, accurately modeling such interfaces is challenging due to the complex interplay between the subsystems. We employ a computational framework integrating first-principles methods, including GW, density functional theory (DFT), and the polarizable continuum model, to elucidate the electronic structure of mixed-dimensional heterojunctions formed by free-base phthalocyanines and monolayer molybdenum disulfide. We assess the impact of dielectric screening across various scenarios, from isolated molecules to organic films on a substrate-supported monolayer. Our findings show that while polarization effects cause significant renormalization of molecular energy levels, band energies and alignments in the most relevant setup can be accurately predicted through DFT simulations of the individual subsystems. Additionally, we analyze orbital hybridization, revealing potential pathways for interfacial charge transfer. This study offers new insights into hybrid inorganic/organic interfaces and provides a practical computational protocol suitable for scaled-up studies.
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Affiliation(s)
- Jannis Krumland
- Institute
of Physics, Carl von Ossietzky Universität
Oldenburg, 26129 Oldenburg, Germany
- Physics
Department and IRIS Adlershof, Humboldt-Universität
zu Berlin, 12489 Berlin, Germany
| | - Caterina Cocchi
- Institute
of Physics, Carl von Ossietzky Universität
Oldenburg, 26129 Oldenburg, Germany
- Physics
Department and IRIS Adlershof, Humboldt-Universität
zu Berlin, 12489 Berlin, Germany
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3
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Liu Y, Handa T, Olsen N, Nuckolls C, Zhu X. Spin-Polarized Charge Separation at Two-Dimensional Semiconductor/Molecule Interfaces. J Am Chem Soc 2024; 146:10052-10059. [PMID: 38536668 DOI: 10.1021/jacs.4c00956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Spin-polarized electrons can improve the efficiency and selectivity of photo- and electro-catalytic reactions, as demonstrated in the past with magnetic or magnetized catalysts. Here, we present a scheme in which spin-polarized charge separation occurs at the interfaces of nonmagnetic semiconductors and molecular films in the absence of a magnetic field. We take advantage of the spin-valley-locked band structure and valley-dependent optical selection rule in group VI transition metal dichalcogenide (TMDC) monolayers to generate spin-polarized electron-hole pairs. Photoinduced electron transfer from WS2 to fullerene (C60) and hole transfer from MoSe2 to phthalocyanine (H2Pc) are found to result in spin polarization lifetimes that are 1 order of magnitude longer than those in the TMDC monolayers alone. Our findings connect valleytronic properties of TMDC monolayers to spin-polarized interfacial charge transfer and suggest a viable route toward spin-selective photocatalysis.
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Affiliation(s)
- Yufeng Liu
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Taketo Handa
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Nicholas Olsen
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Colin Nuckolls
- Department of Chemistry, Columbia University, New York, New York 10027, United States
| | - Xiaoyang Zhu
- Department of Chemistry, Columbia University, New York, New York 10027, United States
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4
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Obaidulla SM, Supina A, Kamal S, Khan Y, Kralj M. van der Waals 2D transition metal dichalcogenide/organic hybridized heterostructures: recent breakthroughs and emerging prospects of the device. NANOSCALE HORIZONS 2023; 9:44-92. [PMID: 37902087 DOI: 10.1039/d3nh00310h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
The near-atomic thickness and organic molecular systems, including organic semiconductors and polymer-enabled hybrid heterostructures, of two-dimensional transition metal dichalcogenides (2D-TMDs) can modulate their optoelectronic and transport properties outstandingly. In this review, the current understanding and mechanism of the most recent and significant breakthrough of novel interlayer exciton emission and its modulation by harnessing the band energy alignment between TMDs and organic semiconductors in a TMD/organic (TMDO) hybrid heterostructure are demonstrated. The review encompasses up-to-date device demonstrations, including field-effect transistors, detectors, phototransistors, and photo-switchable superlattices. An exploration of distinct traits in 2D-TMDs and organic semiconductors delves into the applications of TMDO hybrid heterostructures. This review provides insights into the synthesis of 2D-TMDs and organic layers, covering fabrication techniques and challenges. Band bending and charge transfer via band energy alignment are explored from both structural and molecular orbital perspectives. The progress in emission modulation, including charge transfer, energy transfer, doping, defect healing, and phase engineering, is presented. The recent advancements in 2D-TMDO-based optoelectronic synaptic devices, including various 2D-TMDs and organic materials for neuromorphic applications are discussed. The section assesses their compatibility for synaptic devices, revisits the operating principles, and highlights the recent device demonstrations. Existing challenges and potential solutions are discussed. Finally, the review concludes by outlining the current challenges that span from synthesis intricacies to device applications, and by offering an outlook on the evolving field of emerging TMDO heterostructures.
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Affiliation(s)
- Sk Md Obaidulla
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
- Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Sector III, Block JD, Salt Lake, Kolkata 700106, India
| | - Antonio Supina
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
- Chair of Physics, Montanuniversität Leoben, Franz Josef Strasse 18, 8700 Leoben, Austria
| | - Sherif Kamal
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
| | - Yahya Khan
- Department of Physics, Karakoram International university (KIU), Gilgit 15100, Pakistan
| | - Marko Kralj
- Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Bijenička Cesta 46, HR-10000 Zagreb, Croatia.
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5
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Rijal K, Amos S, Valencia-Acuna P, Rudayni F, Fuller N, Zhao H, Peelaers H, Chan WL. Nanoscale Periodic Trapping Sites for Interlayer Excitons Built by Deformable Molecular Crystal on 2D Crystal. ACS NANO 2023; 17:7775-7786. [PMID: 37042658 DOI: 10.1021/acsnano.3c00541] [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 nanoscale moiré pattern formed at 2D transition-metal dichalcogenide crystal (TMDC) heterostructures provides periodic trapping sites for excitons, which is essential for realizing various exotic phases such as artificial exciton lattices, Bose-Einstein condensates, and exciton insulators. At organic molecule/TMDC heterostructures, similar periodic potentials can be formed via other degrees of freedom. Here, we utilize the structure deformability of a 2D molecular crystal as a degree of freedom to create a periodic nanoscale potential that can trap interlayer excitons (IXs). Specifically, two semiconducting molecules, PTCDI and PTCDA, which possess similar band gaps and ionization potentials but form different lattice structures on MoS2, are investigated. The PTCDI lattice on MoS2 is distorted geometrically, which lifts the degeneracy of the two molecules within the crystal's unit cell. The degeneracy lifting results in a spatial variation of the molecular orbital energy, with an amplitude and periodicity of ∼0.2 eV and ∼2 nm, respectively. On the other hand, no such energy variation is observed in PTCDA/MoS2, where the PTCDA lattice is much less distorted. The periodic variation in molecular orbital energies provides effective trapping sites for IXs. For IXs formed at PTCDI/MoS2, rapid spatial localization of the electron in the organic layer toward the interface is observed, which demonstrates the effectiveness of these interfacial IX traps.
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Affiliation(s)
- Kushal Rijal
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Stephanie Amos
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Pavel Valencia-Acuna
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Fatimah Rudayni
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
- Department of Physics, Jazan University, Jazan 45142, Saudi Arabia
| | - Neno Fuller
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Hui Zhao
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Hartwin Peelaers
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Wai-Lun Chan
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
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6
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Valencia-Acuna P, Rudayni F, Rijal K, Chan WL, Zhao H. Hybrid Heterostructures to Generate Long-Lived and Mobile Photocarriers in Graphene. ACS NANO 2023; 17:3939-3947. [PMID: 36795092 DOI: 10.1021/acsnano.2c12577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
We report the generation of long-lived and highly mobile photocarriers in hybrid van der Waals heterostructures that are formed by monolayer graphene, few-layer transition metal dichalcogenides, and the organic semiconductor F8ZnPc. Samples are fabricated by dry transfer of mechanically exfoliated MoS2 or WS2 few-layer flakes on a graphene film, followed by deposition of F8ZnPc. Transient absorption microscopy measurements are performed to study the photocarrier dynamics. In heterostructures of F8ZnPc/few-layer-MoS2/graphene, electrons excited in F8ZnPc can transfer to graphene and thus be separated from the holes that reside in F8ZnPc. By increasing the thickness of MoS2, these electrons acquire long recombination lifetimes of over 100 ps and a high mobility of 2800 cm2 V-1 s-1. Graphene doping with mobile holes is also demonstrated with WS2 as the middle layers. These artificial heterostructures can improve the performance of graphene-based optoelectronic devices.
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Affiliation(s)
- Pavel Valencia-Acuna
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Fatimah Rudayni
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
- Department of Physics, Jazan University, Jazan 45142, Saudi Arabia
| | - Kushal Rijal
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Wai-Lun Chan
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Hui Zhao
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
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7
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Ji J, Choi JH. Recent progress in 2D hybrid heterostructures from transition metal dichalcogenides and organic layers: properties and applications in energy and optoelectronics fields. NANOSCALE 2022; 14:10648-10689. [PMID: 35839069 DOI: 10.1039/d2nr01358d] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Atomically thin transition metal dichalcogenides (TMDs) present extraordinary optoelectronic, electrochemical, and mechanical properties that have not been accessible in bulk semiconducting materials. Recently, a new research field, 2D hybrid heteromaterials, has emerged upon integrating TMDs with molecular systems, including organic molecules, polymers, metal-organic frameworks, and carbonaceous materials, that can tailor the TMD properties and exploit synergetic effects. TMD-based hybrid heterostructures can meet the demands of future optoelectronics, including supporting flexible, transparent, and ultrathin devices, and energy-based applications, offering high energy and power densities with long cycle lives. To realize such applications, it is necessary to understand the interactions between the hybrid components and to develop strategies for exploiting the distinct benefits of each component. Here, we provide an overview of the current understanding of the new phenomena and mechanisms involved in TMD/organic hybrids and potential applications harnessing such valuable materials in an insightful way. We highlight recent discoveries relating to multicomponent hybrid materials. Finally, we conclude this review by discussing challenges related to hybrid heteromaterials and presenting future directions and opportunities in this research field.
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Affiliation(s)
- Jaehoon Ji
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
| | - Jong Hyun Choi
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
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8
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Melani G, Guerrero-Felipe JP, Valencia AM, Krumland J, Cocchi C, Iannuzzi M. Donors, acceptors, and a bit of aromatics: electronic interactions of molecular adsorbates on hBN and MoS 2 monolayers. Phys Chem Chem Phys 2022; 24:16671-16679. [PMID: 35766517 DOI: 10.1039/d2cp01502a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The design of low-dimensional organic-inorganic interfaces for the next generation of opto-electronic applications requires in-depth understanding of the microscopic mechanisms ruling electronic interactions in these systems. In this work, we present a first-principles study based on density-functional theory inspecting the structural, energetic, and electronic properties of five molecular donors and acceptors adsorbed on freestanding hexagonal boron nitride (hBN) and molybdenum disulfide (MoS2) monolayers. All considered interfaces are stable, due to the crucial contribution of dispersion interactions, which are maximized by the overall flat arrangement of the physisorbed molecules on both substrates. The level alignment of the hybrid systems depends on the characteristics of the constituents. On hBN, both type-I and type-II interfaces may form, depending on the relative energies of the frontier orbitals with respect to the vacuum level. On the other hand, all MoS2-based hybrid systems exhibit a type-II level alignment, with the molecular frontier orbitals positioned across the energy gap of the semiconductor. The electronic structure of the hybrid materials is further determined by the formation of interfacial dipole moments and by the wave-function hybridization between the organic and inorganic constituents. These results provide important indications for the design of novel low-dimensional hybrid materials with suitable characteristics for opto-electronics.
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Affiliation(s)
- Giacomo Melani
- Department of Chemistry, Universität Zürich, 8057 Zürich, Switzerland. .,Present Address: Pritzker School of Molecular Engineering, University of Chicago, 60637, Chicago, USA
| | - Juan Pablo Guerrero-Felipe
- Physics Department and IRIS Adlesrshof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany. .,Department of Physics, Free University Berlin, 14195 Berlin, Germany
| | - Ana M Valencia
- Physics Department and IRIS Adlesrshof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany. .,Institute of Physics, Carl-von-Ossietzy Universität Oldenburg, 26129 Oldenburg, Germany
| | - Jannis Krumland
- Physics Department and IRIS Adlesrshof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.
| | - Caterina Cocchi
- Physics Department and IRIS Adlesrshof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany. .,Institute of Physics, Carl-von-Ossietzy Universität Oldenburg, 26129 Oldenburg, Germany
| | - Marcella Iannuzzi
- Department of Chemistry, Universität Zürich, 8057 Zürich, Switzerland.
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9
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Lei Y, Zheng Z, Vasquez L, Zhao J, Ma J, Ma H. Enhanced Electron Transfer and Spin Flip through Spin-Orbital Couplings in Organic/Inorganic Heterojunctions: A Nonadiabatic Surface Hopping Simulation. J Phys Chem Lett 2022; 13:4840-4848. [PMID: 35616399 DOI: 10.1021/acs.jpclett.2c01177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The circumstances of transferred electrons across organic/inorganic interfaces have attracted intensive interest because of the distinctive electronic structure properties of those two components. Leveraging ab initio nonadiabatic molecular dynamics methods in conjunction with spin dynamics induced by spin-orbital couplings (SOCs), this study reports two competitive channels during photoinduced dynamical processes in the prototypical ZnPc/monolayer MoS2 heterojunction. Interestingly, the electron-transfer and relaxation processes occur simultaneously because of the enhancement of electron-phonon couplings and expansion of dynamical pathways by SOCs, suggesting that the electron-transfer rate and relaxation processes can be tuned by SOCs, hence yielding the performance promotion of photovoltaic and photocatalytic devices. Additionally, approximately half of the transferred electrons flip their spin within 1.6 ps because of strong SOCs in MoS2, achieving great agreement with experimental measurements. This investigation provides instructive perspectives for designing novel devices and applications based on organic/inorganic heterojunctions, demonstrating the importance of spin dynamics simulations in exploring sophisticated photoinduced processes in materials.
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Affiliation(s)
- Yuli Lei
- Jiangsu Key Laboratory of Vehicle Emissions Control, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Zhenfa Zheng
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Luis Vasquez
- Jiangsu Key Laboratory of Vehicle Emissions Control, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jin Zhao
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jing Ma
- Jiangsu Key Laboratory of Vehicle Emissions Control, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Haibo Ma
- Jiangsu Key Laboratory of Vehicle Emissions Control, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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10
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Zhao Y, Gobbi M, Hueso LE, Samorì P. Molecular Approach to Engineer Two-Dimensional Devices for CMOS and beyond-CMOS Applications. Chem Rev 2021; 122:50-131. [PMID: 34816723 DOI: 10.1021/acs.chemrev.1c00497] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Two-dimensional materials (2DMs) have attracted tremendous research interest over the last two decades. Their unique optical, electronic, thermal, and mechanical properties make 2DMs key building blocks for the fabrication of novel complementary metal-oxide-semiconductor (CMOS) and beyond-CMOS devices. Major advances in device functionality and performance have been made by the covalent or noncovalent functionalization of 2DMs with molecules: while the molecular coating of metal electrodes and dielectrics allows for more efficient charge injection and transport through the 2DMs, the combination of dynamic molecular systems, capable to respond to external stimuli, with 2DMs makes it possible to generate hybrid systems possessing new properties by realizing stimuli-responsive functional devices and thereby enabling functional diversification in More-than-Moore technologies. In this review, we first introduce emerging 2DMs, various classes of (macro)molecules, and molecular switches and discuss their relevant properties. We then turn to 2DM/molecule hybrid systems and the various physical and chemical strategies used to synthesize them. Next, we discuss the use of molecules and assemblies thereof to boost the performance of 2D transistors for CMOS applications and to impart diverse functionalities in beyond-CMOS devices. Finally, we present the challenges, opportunities, and long-term perspectives in this technologically promising field.
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Affiliation(s)
- Yuda Zhao
- University of Strasbourg, CNRS, ISIS UMR 7006, 8 allée Gaspard Monge, F-67000 Strasbourg, France.,School of Micro-Nano Electronics, ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Zhejiang University, 38 Zheda Road, 310027 Hangzhou, People's Republic of China
| | - Marco Gobbi
- Centro de Fisica de Materiales (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, E-20018 Donostia-San Sebastián, Spain.,CIC nanoGUNE, E-20018 Donostia-San Sebastian, Basque Country, Spain.,IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Spain
| | - Luis E Hueso
- CIC nanoGUNE, E-20018 Donostia-San Sebastian, Basque Country, Spain.,IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Spain
| | - Paolo Samorì
- University of Strasbourg, CNRS, ISIS UMR 7006, 8 allée Gaspard Monge, F-67000 Strasbourg, France
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11
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Wanigasekara S, Kattel B, Rudayni F, Chan WL. Extracting Electrons from Delocalized Excitons by Flattening the Energetic Pathway for Charge Separation. J Phys Chem Lett 2021; 12:9047-9054. [PMID: 34516118 DOI: 10.1021/acs.jpclett.1c02228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
At organic donor-acceptor (D-A) interfaces, electron and hole are bound together to form charge transfer (CT) excitons. The electron and hole wave functions in these CT excitons can spatially delocalize. The electron delocalization opens up possibilities of extracting free charges from bound excitons by manipulating the potential energy landscape on the nanoscale. Using a prototype trilayer structure that has a cascade band structure, we show that the yield of charge separation can be doubled as compared to the bilayer counterpart when the thickness of the intermediate layer is around 3 nm. This thickness coincides with the electron delocalization size of CT excitons typically found in these organic films. Tight-binding calculation for the CT states in the trilayer structure further demonstrates that electron delocalization, together with the energy level cascade, can effectively flatten the energetic pathway for charge separation. Hence, it is possible to add nanometer-thick layers between the donor and the acceptor to significantly enhance the charge separation yield.
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Affiliation(s)
- Shanika Wanigasekara
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Bhupal Kattel
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Fatimah Rudayni
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
| | - Wai-Lun Chan
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States
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12
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Maiti S, Poonia D, Schiettecatte P, Hens Z, Geiregat P, Kinge S, Siebbeles LD. Generating Triplets in Organic Semiconductor Tetracene upon Photoexcitation of Transition Metal Dichalcogenide ReS 2. J Phys Chem Lett 2021; 12:5256-5260. [PMID: 34048249 PMCID: PMC8201445 DOI: 10.1021/acs.jpclett.1c01411] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We studied the dynamics of transfer of photoexcited electronic states in a bilayer of the two-dimensional transition metal dichalcogenide ReS2 and tetracene, with the aim to produce triplets in the latter. This material combination was used as the band gap of ReS2 (1.5 eV) is slightly larger than the triplet energy of tetracene (1.25 eV). Using time-resolved optical absorption spectroscopy, transfer of photoexcited states from ReS2 to triplet states in tetracene was found to occur within 5 ps with an efficiency near 38%. This result opens up new possibilities for heterostructure design of two-dimensional materials with suitable organics to produce long-lived triplets. Triplets are of interest as sensitizers in a wide variety of applications including optoelectronics, photovoltaics, photocatalysis, and photon upconversion.
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Affiliation(s)
- Sourav Maiti
- Optoelectronic
Materials Section, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
| | - Deepika Poonia
- Optoelectronic
Materials Section, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
| | - Pieter Schiettecatte
- Physics
and Chemistry of Nanostructures, Ghent University, Ghent, Belgium
- Center
for Nano and Biophotonics, Ghent University, Ghent, Belgium
| | - Zeger Hens
- Physics
and Chemistry of Nanostructures, Ghent University, Ghent, Belgium
- Center
for Nano and Biophotonics, Ghent University, Ghent, Belgium
| | - Pieter Geiregat
- Physics
and Chemistry of Nanostructures, Ghent University, Ghent, Belgium
- Center
for Nano and Biophotonics, Ghent University, Ghent, Belgium
| | - Sachin Kinge
- Optoelectronic
Materials Section, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
- Toyota
Motor Europe, Materials Research & Development, Hoge Wei 33, B-1913 Zaventem, Belgium
| | - Laurens D.A. Siebbeles
- Optoelectronic
Materials Section, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
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13
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Park S, Mutz N, Kovalenko SA, Schultz T, Shin D, Aljarb A, Li L, Tung V, Amsalem P, List‐Kratochvil EJW, Stähler J, Xu X, Blumstengel S, Koch N. Type-I Energy Level Alignment at the PTCDA-Monolayer MoS 2 Interface Promotes Resonance Energy Transfer and Luminescence Enhancement. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2100215. [PMID: 34194946 PMCID: PMC8224443 DOI: 10.1002/advs.202100215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/24/2021] [Indexed: 06/13/2023]
Abstract
Van der Waals heterostructures consisting of 2D semiconductors and conjugated molecules are of increasing interest because of the prospect of a synergistic enhancement of (opto)electronic properties. In particular, perylenetetracarboxylic dianhydride (PTCDA) on monolayer (ML)-MoS2 has been identified as promising candidate and a staggered type-II energy level alignment and excited state interfacial charge transfer have been proposed. In contrast, it is here found with inverse and direct angle resolved photoelectron spectroscopy that PTCDA/ML-MoS2 supported by insulating sapphire exhibits a straddling type-I level alignment, with PTCDA having the wider energy gap. Photoluminescence (PL) and sub-picosecond transient absorption measurements reveal that resonance energy transfer, i.e., electron-hole pair (exciton) transfer, from PTCDA to ML-MoS2 occurs on a sub-picosecond time scale. This gives rise to an enhanced PL yield from ML-MoS2 in the heterostructure and an according overall modulation of the photoresponse. These results underpin the importance of a precise knowledge of the interfacial electronic structure in order to understand excited state dynamics and to devise reliable design strategies for optimized optoelectronic functionality in van der Waals heterostructures.
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Affiliation(s)
- Soohyung Park
- Advanced Analysis CenterKorea Institute of Science and Technology (KIST)Seoul02792South Korea
| | - Niklas Mutz
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
| | | | - Thorsten Schultz
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
- Helmholtz‐Zentrum für Materialien und Energie GmbHBerlin12489Germany
| | - Dongguen Shin
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
| | - Areej Aljarb
- Physical Sciences and EngineeringKing Abdullah University of Science and TechnologyThuwal23955‐6900Saudi Arabia
| | - Lain‐Jong Li
- Department of Mechanical EngineeringThe University of Hong KongPokfulam RoadHong Kong
| | - Vincent Tung
- Physical Sciences and EngineeringKing Abdullah University of Science and TechnologyThuwal23955‐6900Saudi Arabia
| | - Patrick Amsalem
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
| | - Emil J. W. List‐Kratochvil
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
- Humboldt‐Universität zu BerlinInstitut für ChemieBerlin12489Germany
- Helmholtz‐Zentrum für Materialien und Energie GmbHBerlin12489Germany
| | - Julia Stähler
- Humboldt‐Universität zu BerlinInstitut für ChemieBerlin12489Germany
| | - Xiaomin Xu
- Shenzhen Geim Graphene CenterTsinghua‐Berkeley Shenzhen InstituteTsinghua UniversityShenzhen518055China
| | - Sylke Blumstengel
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
- Humboldt‐Universität zu BerlinInstitut für ChemieBerlin12489Germany
| | - Norbert Koch
- Humboldt‐Universität zu BerlinInstitut für Physik & IRIS AdlershofBerlin12489Germany
- Helmholtz‐Zentrum für Materialien und Energie GmbHBerlin12489Germany
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14
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Amsterdam SH, Marks TJ, Hersam MC. Leveraging Molecular Properties to Tailor Mixed-Dimensional Heterostructures beyond Energy Level Alignment. J Phys Chem Lett 2021; 12:4543-4557. [PMID: 33970639 DOI: 10.1021/acs.jpclett.1c00799] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The surface sensitivity and lack of dielectric screening in two-dimensional (2D) materials provide numerous intriguing opportunities to tailor their properties using adsorbed π-electron organic molecules. These organic-2D mixed-dimensional heterojunctions are often considered solely in terms of their energy level alignment, i.e., the relative energies of the frontier molecular orbitals versus the 2D material conduction and valence band edges. While this simple model is frequently adequate to describe doping and photoinduced charge transfer, the tools of molecular chemistry enable additional manipulation of properties in organic-2D heterojunctions that are not accessible in other solid-state systems. Fully exploiting these possibilities requires consideration of the details of the organic adlayer beyond its energy level alignment, including hybridization and electrostatics, molecular orientation and thin-film morphology, nonfrontier orbitals and defects, excitonic states, spin, and chirality. This Perspective explores how these relatively overlooked molecular properties offer unique opportunities for tuning optical and electronic characteristics, thereby guiding the rational design of organic-2D mixed-dimensional heterojunctions with emergent properties.
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Affiliation(s)
- Samuel H Amsterdam
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Tobin J Marks
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
- Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Mark C Hersam
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
- Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
- Applied Physics Program, Northwestern University, Evanston, Illinois 60208, United States
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208, United States
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15
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Zhao C, Tao W, Chen Z, Zhou H, Zhang C, Lin J, Zhu H. Ultrafast Electron Transfer with Long-Lived Charge Separation and Spin Polarization in WSe 2/C 60 Heterojunction. J Phys Chem Lett 2021; 12:3691-3697. [PMID: 33829780 DOI: 10.1021/acs.jpclett.1c00848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The strong excitonic effect in monolayer transition-metal dichalcogenides (TMDs) endows them with intriguing optoelectronic properties but also short-lived population and valley polarization. Exciton dissociation by interfacial charge transfer has been shown as an effective approach to prolonging excited-state lifetimes. Herein, by ultrafast spectroscopy and building-block molecule C60, we investigated exciton and valley polarization dynamics in the prototypical WSe2/C60 inorganic-organic hybrid. We show that excitons in WSe2 can be dissociated through ultrafast (∼1 ps) electron transfer to C60, with nanosecond charge separation due to thermally activated electron diffusion in C60 film. Because of suppressed electron-hole exchange interaction after electron transfer, hole in WSe2 exhibits a spin/valley polarization lifetime of ∼60 ps at room temperature, more than 2 orders of magnitude longer than that in WSe2 monolayer. This study suggests exciton dissociation as a general approach to suppress electron-hole interaction and prolong the charge/spin/valley lifetime in TMDs.
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Affiliation(s)
- Chang Zhao
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China
| | - Weijian Tao
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zeng Chen
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China
| | - Hongzhi Zhou
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China
| | - Chi Zhang
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China
| | - Junyi Lin
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China
| | - Haiming Zhu
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, China
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