1
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Jing Y, Liang K, Muir NS, Zhou H, Li Z, Palasz JM, Sorbie J, Wang C, Cushing SK, Kubiak CP, Sofer Z, Li S, Xiong W. Ultrafast Formation of Charge Transfer Trions at Molecular-Functionalized 2D MoS 2 Interfaces. Angew Chem Int Ed Engl 2024; 63:e202405123. [PMID: 38714495 DOI: 10.1002/anie.202405123] [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: 03/18/2024] [Revised: 05/03/2024] [Accepted: 05/07/2024] [Indexed: 05/10/2024]
Abstract
In this work, we investigate trion dynamics occurring at the heterojunction between organometallic molecules and a monolayer transition metal dichalcogenide (TMD) with transient electronic sum frequency generation (tr-ESFG) spectroscopy. By pumping at 2.4 eV with laser pulses, we have observed an ultrafast hole transfer, succeeded by the emergence of charge-transfer trions. This observation is facilitated by the cancellation of ground state bleach and stimulated emission signals due to their opposite phases, making tr-ESFG especially sensitive to the trion formation dynamics. The presence of charge-transfer trion at molecular functionalized TMD monolayers suggests the potential for engineering the local electronic structures and dynamics of specific locations on TMDs and offers a potential for transferring unique electronic attributes of TMD to the molecular layers.
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Affiliation(s)
- Yuancheng Jing
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California, 92093-0358, United States
| | - Kangkai Liang
- Material Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, MC 0418, La Jolla, California, 92093-0418, United States
| | - Nicole S Muir
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California, 92093-0358, United States
| | - Hao Zhou
- Material Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, MC 0418, La Jolla, California, 92093-0418, United States
| | - Zhehao Li
- Material Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, MC 0418, La Jolla, California, 92093-0418, United States
| | - Joseph M Palasz
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California, 92093-0358, United States
| | - Jonathan Sorbie
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California, 92093-0358, United States
| | - Chenglai Wang
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California, 92093-0358, United States
| | - Scott K Cushing
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd, MC 127-72, Pasadena, California, 91125, United States
| | - Clifford P Kubiak
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California, 92093-0358, United States
| | - Zdeněk Sofer
- Department of Inorganic Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Czech Republic
| | - Shaowei Li
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California, 92093-0358, United States
- Material Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, MC 0418, La Jolla, California, 92093-0418, United States
| | - Wei Xiong
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California, 92093-0358, United States
- Material Science and Engineering Program, University of California, San Diego, 9500 Gilman Drive, MC 0418, La Jolla, California, 92093-0418, United States
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2
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Meng Y, Wang W, Wang W, Li B, Zhang Y, Ho J. Anti-Ambipolar Heterojunctions: Materials, Devices, and Circuits. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2306290. [PMID: 37580311 DOI: 10.1002/adma.202306290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/31/2023] [Indexed: 08/16/2023]
Abstract
Anti-ambipolar heterojunctions are vital in constructing high-frequency oscillators, fast switches, and multivalued logic (MVL) devices, which hold promising potential for next-generation integrated circuit chips and telecommunication technologies. Thanks to the strategic material design and device integration, anti-ambipolar heterojunctions have demonstrated unparalleled device and circuit performance that surpasses other semiconducting material systems. This review aims to provide a comprehensive summary of the achievements in the field of anti-ambipolar heterojunctions. First, the fundamental operating mechanisms of anti-ambipolar devices are discussed. After that, potential materials used in anti-ambipolar devices are discussed with particular attention to 2D-based, 1D-based, and organic-based heterojunctions. Next, the primary device applications employing anti-ambipolar heterojunctions, including anti-ambipolar transistors (AATs), photodetectors, frequency doublers, and synaptic devices, are summarized. Furthermore, alongside the advancements in individual devices, the practical integration of these devices at the circuit level, including topics such as MVL circuits, complex logic gates, and spiking neuron circuits, is also discussed. Lastly, the present key challenges and future research directions concerning anti-ambipolar heterojunctions and their applications are also emphasized.
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Affiliation(s)
- You Meng
- Department of Materials Science and Engineering, State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Weijun Wang
- Department of Materials Science and Engineering, State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Wei Wang
- Department of Materials Science and Engineering, State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Bowen Li
- Department of Materials Science and Engineering, State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Yuxuan Zhang
- Department of Materials Science and Engineering, State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Johnny Ho
- Department of Materials Science and Engineering, State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
- Institute for Materials Chemistry and Engineering, Kyushu University, Fukuoka, 816-8580, Japan
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3
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Dziobek-Garrett R, Imperiale CJ, Wilson MWB, Kempa TJ. Photon Upconversion in a Vapor Deposited 2D Inorganic-Organic Semiconductor Heterostructure. NANO LETTERS 2023. [PMID: 37191568 DOI: 10.1021/acs.nanolett.3c00380] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Energy transfer processes may be engineered in van der Waals heterostructures by taking advantage of the atomically abrupt, Å-scale, and topologically tailorable interfaces within them. Here, we prepare heterostructures comprised of 2D WSe2 monolayers interfaced with dibenzotetraphenylperiflanthene (DBP)-doped rubrene, an organic semiconductor capable of triplet fusion. We fabricate these heterostructures entirely through vapor deposition methods. Time-resolved and steady-state photoluminescence measurements reveal rapid subnanosecond quenching of WSe2 emission by rubrene and fluorescence from guest DBP molecules at 612 nm (λexc = 730 nm), thus providing clear evidence of photon upconversion. The dependence of the upconversion emission on excitation intensity is consistent with a triplet fusion mechanism, and maximum efficiency (linear regime) of this process occurs at threshold intensities as low as 110 mW/cm2, which is comparable to the integrated solar irradiance. This study highlights the potential for advanced optoelectronic applications employing vdWHs which leverage strongly bound excitons in monolayer TMDs and organic semiconductors.
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Affiliation(s)
| | | | - Mark W B Wilson
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Thomas J Kempa
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Department of Materials Science & Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
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4
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Amsterdam SH, Stanev TK, Wang L, Zhou Q, Irgen-Gioro S, Padgaonkar S, Murthy AA, Sangwan VK, Dravid VP, Weiss EA, Darancet P, Chan MKY, Hersam MC, Stern NP, Marks TJ. Mechanistic Investigation of Molybdenum Disulfide Defect Photoluminescence Quenching by Adsorbed Metallophthalocyanines. J Am Chem Soc 2021; 143:17153-17161. [PMID: 34613735 DOI: 10.1021/jacs.1c07795] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Lattice defects play an important role in determining the optical and electrical properties of monolayer semiconductors such as MoS2. Although the structures of various defects in monolayer MoS2 are well studied, little is known about the nature of the fluorescent defect species and their interaction with molecular adsorbates. In this study, the quenching of the low-temperature defect photoluminescence (PL) in MoS2 is investigated following the deposition of metallophthalocyanines (MPcs). The quenching is found to significantly depend on the identity of the phthalocyanine metal, with the quenching efficiency decreasing in the order CoPc > CuPc > ZnPc, and almost no quenching by metal-free H2Pc is observed. Time-correlated single photon counting (TCSPC) measurements corroborate the observed trend, indicating a decrease in the defect PL lifetime upon MPc adsorption, and the gate voltage-dependent PL reveals the suppression of the defect emission even at large Fermi level shifts. Density functional theory modeling argues that the MPc complexes stabilize dark negatively charged defects over luminescent neutral defects through an electrostatic local gating effect. These results demonstrate the control of defect-based excited-state decay pathways via molecular electronic structure tuning, which has broad implications for the design of mixed-dimensional optoelectronic devices.
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Affiliation(s)
- Samuel H Amsterdam
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Teodor K Stanev
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
| | - Luqing Wang
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Qunfei Zhou
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Shawn Irgen-Gioro
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Suyog Padgaonkar
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Akshay A Murthy
- Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Vinod K Sangwan
- Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Vinayak P Dravid
- Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States.,Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Evanston, Illinois 60208, United States
| | - Emily A Weiss
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States.,Department of Physics and Astronomy, 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
| | - Pierre Darancet
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Northwestern Argonne Institute of Science and Engineering, Evanston, Illinois 60208, United States
| | - Maria K Y Chan
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Northwestern Argonne Institute of Science and Engineering, 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.,Department of Electrical and Computer Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Nathaniel P Stern
- Department of Physics and Astronomy, 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
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5
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Wei Y, Zhang F, Wei J, Yang Z. CdSe 1D/2D Mixed-Dimensional Heterostructures: Curvature-Complementary Self-Assembly for Enhanced Visible-Light Photocatalysis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2102047. [PMID: 34254443 DOI: 10.1002/smll.202102047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/05/2021] [Indexed: 06/13/2023]
Abstract
Mixed-dimensional heterostructures (MDHs), which combine nanomaterials of different dimensionalities deliver on the promise to bypass intrinsic limitations of a given low-dimensional material. Here, a strategy to engineer MDHs between two low-dimensional materials by curvature-complementary self-assembly is described. CdSe nanotubes rolled from 2D nanosheets and 1D CdSe nanorods, with negative and positive curvatures, respectively, are selected to illustrate complementary curvature self-assembly. The assembly process, optical, and photoelectrical properties of the CdSe MDHs are thoroughly investigated. Several remarkable features of CdSe MDHs, including increased light absorption, efficient charge separation, and appropriate bandgap structure are confirmed. The MDHs significantly alleviate the sluggish kinetics of electron transfer in the quantum sized CdSe subunits (onset potential of 0.21 V vs RHE for MDHs; 0.4 V lower than their low-dimensional building blocks), while the spatial nano-confinement effect in the CdSe MDHs also assists the interfacial reaction kinetics to render them ideal photocatalysts for benzylamine oxidation (conversion > 99% in 4 h with a two times higher rate than simple mixtures). The results highlight opportunities for building MDHs from low-dimensional building blocks with curvature-complementary features and expand the application spectrum of low dimensional materials in artificial photosynthesis.
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Affiliation(s)
- Yanze Wei
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, 250100, China
| | - Fenghua Zhang
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, 250100, China
| | - Jingjing Wei
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, 250100, China
| | - Zhijie Yang
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan, 250100, China
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6
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Zhou Q, Liu ZF, Marks TJ, Darancet P. Electronic Structure of Metallophthalocyanines, MPc (M = Fe, Co, Ni, Cu, Zn, Mg) and Fluorinated MPc. J Phys Chem A 2021; 125:4055-4061. [PMID: 33961423 DOI: 10.1021/acs.jpca.0c10766] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We compute the electronic structure and optical excitation energies of metal-free and transition-metal phthalocyanines (H2Pc and MPc for M = Fe, Co, Ni, Cu, Zn, Mg) using density functional theory with optimally tuned range-separated hybrid functionals (OT-RSH). We show that the OT-RSH approach provides photoemission spectra in quantitative agreement with experiments as well as optical band gaps within 10% of their experimental values, capturing the interplay of localized d-states and delocalized π-π* states for these organometallic compounds. We examine the tunability of MPcs and H2Pc through fluorination, resulting in quasi-rigid shifts of the molecular orbital energies by up to 0.7 eV. Our comprehensive data set provides a new computational benchmark for gas-phase phthalocyanines, significantly improving upon other density-functional-theory-based approaches.
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Affiliation(s)
- Qunfei Zhou
- Materials Research Science and Engineering Center, Northwestern University, Evanston, Illinois 60208, United States.,Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Zhen-Fei Liu
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States
| | - Tobin J Marks
- Materials Research Science and Engineering Center, Northwestern University, Evanston, Illinois 60208, United States.,Department of Chemistry and Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Pierre Darancet
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States.,Northwestern Argonne Institute for Science and Engineering, Evanston, Illinois 60208, United States
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7
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Amsterdam SH, LaMountain T, Stanev TK, Sangwan VK, López-Arteaga R, Padgaonkar S, Watanabe K, Taniguchi T, Weiss EA, Marks TJ, Hersam MC, Stern NP. Tailoring the Optical Response of Pentacene Thin Films via Templated Growth on Hexagonal Boron Nitride. J Phys Chem Lett 2021; 12:26-31. [PMID: 33296212 DOI: 10.1021/acs.jpclett.0c03132] [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 optoelectronic properties of organic thin films are strongly dependent on their molecular orientation and packing, which in turn is sensitive to the underlying substrate. Hexagonal boron nitride (hBN) and other van der Waals (vdW) materials are known to template different organic thin film growth modalities from conventional inorganic substrates such as SiO2. Here, the morphology and temperature-dependent optical properties of pentacene films grown on hBN are reported. Pentacene deposited on hBN forms large-grain films with a molecular π-face-on orientation unlike the dendritic edge-on thin-film phase on SiO2. Pentacene/hBN films exhibit a 40 meV lower free exciton emission than pentacene/SiO2 and an unconventional emission energy temperature dependence. Time-resolved photoluminescence (PL) decay measurements show a long-lived signal in the π-face-on phase related to delayed emission from triplet-triplet fusion. This work demonstrates that growth on vdW materials provides a pathway for controlling optoelectronic functionality in molecular thin films.
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Affiliation(s)
- Samuel H Amsterdam
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Trevor LaMountain
- Applied Physics Program, Northwestern University, Evanston, Illinois 60208, United States
| | - Teodor K Stanev
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
| | - Vinod K Sangwan
- Department of Materials Science and Engineering and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Rafael López-Arteaga
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Suyog Padgaonkar
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Emily A Weiss
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
- Applied Physics Program, 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
| | - 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
| | - Mark C Hersam
- Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
- Applied Physics Program, 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 Engineering and Computer Science and the Materials Research Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Nathaniel P Stern
- Applied Physics Program, Northwestern University, Evanston, Illinois 60208, United States
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
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8
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Ko J, Berger R, Lee H, Yoon H, Cho J, Char K. Electronic effects of nano-confinement in functional organic and inorganic materials for optoelectronics. Chem Soc Rev 2021; 50:3585-3628. [DOI: 10.1039/d0cs01501f] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review provides a comprehensive overview of the electronic effects of nano-confinement (from 1D to 3D geometries) on optoelectronic materials and their applications.
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Affiliation(s)
- Jongkuk Ko
- Department of Chemical and Biological Engineering
- Korea University
- Seoul 02841
- Republic of Korea
- School of Chemical & Biological Engineering
| | - Rüdiger Berger
- Physics at Interfaces
- Max Planck Institute for Polymer Research
- D-55128 Mainz
- Germany
| | - Hyemin Lee
- Department of Chemical & Biomolecular Engineering
- Seoul National University of Science & Technology
- Seoul 01811
- Republic of Korea
| | - Hyunsik Yoon
- Department of Chemical & Biomolecular Engineering
- Seoul National University of Science & Technology
- Seoul 01811
- Republic of Korea
| | - Jinhan Cho
- Department of Chemical and Biological Engineering
- Korea University
- Seoul 02841
- Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology
| | - Kookheon Char
- School of Chemical & Biological Engineering
- Seoul National University
- Seoul 08826
- Republic of Korea
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9
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Jin C, Olsen BC, Luber EJ, Buriak JM. van der Waals Epitaxy of Soft Twisted Bilayers: Lattice Relaxation and Mass Density Waves. ACS NANO 2020; 14:13441-13450. [PMID: 32931263 DOI: 10.1021/acsnano.0c05310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Interfaces comprising incommensurate or twisted hexagonal lattices are ubiquitous and of great interest, from adsorbed organic/inorganic interfaces in electronic devices, to superlubricants, and more recently to van der Waals bilayer heterostructures (vdWHs) of graphene and other 2D materials that demonstrate a range of properties such as superconductivity and ferromagnetism. Here we show how growth of 2D crystalline domains of soft block copolymers (BCPs) on patterned hard hexagonal lattices provide fundamental insights into van der Waals heteroepitaxy. At moderate registration forces, it is experimentally found that these BCP-hard lattice vdWHs do not adopt a simple moiré superstructure, but instead adopt local structural relaxations known as mass density waves (MDWs). Simulations reveal that MDWs are a primary mechanism of energy minimization and are the origin of the observed preferential twist angle between the lattices.
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Affiliation(s)
- Cong Jin
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada
| | - Brian C Olsen
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada
| | - Erik J Luber
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada
| | - Jillian M Buriak
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, AB T6G 2G2, Canada
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10
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Rijal K, Rudayni F, Kafle TR, Chan WL. Collective Effects of Band Offset and Wave Function Dimensionality on Impeding Electron Transfer from 2D to Organic Crystals. J Phys Chem Lett 2020; 11:7495-7501. [PMID: 32812767 DOI: 10.1021/acs.jpclett.0c01796] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Excited-state electron transfer (ET) across molecules/transition metal dichalcogenide crystal (TMDC) interfaces is a critical process for the functioning of various organic/TMDC hybrid optoelectronic devices. Therefore, it is important to understand the fundamental factors that can facilitate or limit the ET rate. Here it is found that an undesirable combination of the interfacial band offset and the spatial dimensionality of the delocalized electron wave function can significantly slow down the ET process. Specifically, it is found that whereas the ET rate from TMDCs (MoS2 and WSe2) to fullerenes is relative insensitive to the band offset, the ET rate from TMDCs to perylene molecules can be reduced by an order of magnitude when the band offset is large. For the perylene crystal, the sensitivity of the ET rate on the band offset is explained by the 1D nature of the electronic wave function, which limits the availability of states with the appropriate energy to accept the electron.
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Affiliation(s)
- Kushal Rijal
- 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
| | - Tika R Kafle
- 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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11
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Schultz JF, Li S, Jiang S, Jiang N. Optical scanning tunneling microscopy based chemical imaging and spectroscopy. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:463001. [PMID: 32702674 DOI: 10.1088/1361-648x/aba8c7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Through coupling optical processes with the scanning tunneling microscope (STM), single-molecule chemistry and physics have been investigated at the ultimate spatial and temporal limit. Electrons and photons can be used to drive interactions and reactions in chemical systems and simultaneously probe their characteristics and consequences. In this review we introduce and review methods to couple optical imaging and spectroscopy with scanning tunneling microscopy. The integration of the STM and optical spectroscopy provides new insights into individual molecular adsorbates, surface-supported molecular assemblies, and two-dimensional materials with subnanoscale resolution, enabling the fundamental study of chemistry at the spatial and temporal limit. The inelastic scattering of photons by molecules and materials, that results in unique and sensitive vibrational fingerprints, will be considered with tip-enhanced Raman spectroscopy. STM-induced luminescence examines the intrinsic luminescence of organic adsorbates and their energy transfer and charge transfer processes with their surroundings. We also provide a survey of recent efforts to probe the dynamics of optical excitation at the molecular level with scanning tunneling microscopy in the context of light-induced photophysical and photochemical transformations.
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Affiliation(s)
- Jeremy F Schultz
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, United States of America
| | - Shaowei Li
- Department of Chemistry and Biochemistry, University of California, San Diego, CA 92093, United States of America
- Kavli Energy NanoScience Institute, University of California, Berkeley, CA 94720, United States of America
| | - Song Jiang
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Nan Jiang
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, United States of America
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