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Title: Distinct Optoelectronic Signatures for Charge Transfer and Energy Transfer in Quantum Dot-MoS 2 Hybrid Photodetectors Revealed by Photocurrent Imaging Microscopy

Abstract

Atomically thin transition metal dichalcogenides (TMDCs) have intriguing nanoscale properties like high charge mobility, photosensitivity, layer-thickness-dependent bandgap, and mechanical flexibility, which are all appealing for the development of next generation optoelectronic, catalytic, and sensory devices. Their atomically thin thickness, however, renders TMDCs poor absorptivity. For this study, bilayer MoS 2 is combined with core-only CdSe QDs and core/shell CdSe/ZnS QDs to obtain hybrids with increased light harvesting and exhibiting interfacial charge transfer (CT) and nonradiative energy transfer (NET), respectively. Field-effect transistors based on these hybrids and their responses to varying laser power and applied gate voltage are investigated with scanning photocurrent microscopy (SPCM) in view of their potential utilization in light harvesting and photodetector applications. CdSe–MoS 2 hybrids are found to exhibit encouraging properties for photodetectors, like high responsivity and fast on/off response under low light exposure while CdSe/ZnS–MoS 2 hybrids show enhanced charge carrier generation with increased light exposure, thus suitable for photovoltaics. While distinguishing optically between CT and NET in QD–TMDCs is nontrivial, it is found that they can be differentiated by SPCM as these two processes exhibit distinctive light-intensity dependencies: CT causes a photogating effect, decreasing the photocurrent response with increasing light power while NET increases themore » photocurrent response with increasing light power, opposite to CT case.« less

Authors:
 [1];  [2];  [3];  [1];  [1]; ORCiD logo [1]
  1. Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN); Stony Brook Univ., NY (United States). Dept. of Materials Science and Chemical Engineering
  3. Stony Brook Univ., NY (United States). Dept. of Materials Science and Chemical Engineering; Columbia Univ., New York, NY (United States). Dept. of Physics
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1440894
Alternate Identifier(s):
OSTI ID: 1437667
Report Number(s):
BNL-205746-2018-JAAM
Journal ID: ISSN 1616-301X
Grant/Contract Number:
SC0012704
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Advanced Functional Materials
Additional Journal Information:
Journal Name: Advanced Functional Materials; Journal ID: ISSN 1616-301X
Publisher:
Wiley
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; transition metal dichalcogenides; TMDCs; colloidal quantum dots; light harvesting; excitonic nanomaterials; photocurrent imaging; charge transfer; energy transfer

Citation Formats

Li, Mingxing, Chen, Jia-Shiang, Routh, Prahlad K., Zahl, Percy, Nam, Chang-Yong, and Cotlet, Mircea. Distinct Optoelectronic Signatures for Charge Transfer and Energy Transfer in Quantum Dot-MoS2 Hybrid Photodetectors Revealed by Photocurrent Imaging Microscopy. United States: N. p., 2018. Web. doi:10.1002/adfm.201707558.
Li, Mingxing, Chen, Jia-Shiang, Routh, Prahlad K., Zahl, Percy, Nam, Chang-Yong, & Cotlet, Mircea. Distinct Optoelectronic Signatures for Charge Transfer and Energy Transfer in Quantum Dot-MoS2 Hybrid Photodetectors Revealed by Photocurrent Imaging Microscopy. United States. doi:10.1002/adfm.201707558.
Li, Mingxing, Chen, Jia-Shiang, Routh, Prahlad K., Zahl, Percy, Nam, Chang-Yong, and Cotlet, Mircea. Thu . "Distinct Optoelectronic Signatures for Charge Transfer and Energy Transfer in Quantum Dot-MoS2 Hybrid Photodetectors Revealed by Photocurrent Imaging Microscopy". United States. doi:10.1002/adfm.201707558.
@article{osti_1440894,
title = {Distinct Optoelectronic Signatures for Charge Transfer and Energy Transfer in Quantum Dot-MoS2 Hybrid Photodetectors Revealed by Photocurrent Imaging Microscopy},
author = {Li, Mingxing and Chen, Jia-Shiang and Routh, Prahlad K. and Zahl, Percy and Nam, Chang-Yong and Cotlet, Mircea},
abstractNote = {Atomically thin transition metal dichalcogenides (TMDCs) have intriguing nanoscale properties like high charge mobility, photosensitivity, layer-thickness-dependent bandgap, and mechanical flexibility, which are all appealing for the development of next generation optoelectronic, catalytic, and sensory devices. Their atomically thin thickness, however, renders TMDCs poor absorptivity. For this study, bilayer MoS2 is combined with core-only CdSe QDs and core/shell CdSe/ZnS QDs to obtain hybrids with increased light harvesting and exhibiting interfacial charge transfer (CT) and nonradiative energy transfer (NET), respectively. Field-effect transistors based on these hybrids and their responses to varying laser power and applied gate voltage are investigated with scanning photocurrent microscopy (SPCM) in view of their potential utilization in light harvesting and photodetector applications. CdSe–MoS2 hybrids are found to exhibit encouraging properties for photodetectors, like high responsivity and fast on/off response under low light exposure while CdSe/ZnS–MoS2 hybrids show enhanced charge carrier generation with increased light exposure, thus suitable for photovoltaics. While distinguishing optically between CT and NET in QD–TMDCs is nontrivial, it is found that they can be differentiated by SPCM as these two processes exhibit distinctive light-intensity dependencies: CT causes a photogating effect, decreasing the photocurrent response with increasing light power while NET increases the photocurrent response with increasing light power, opposite to CT case.},
doi = {10.1002/adfm.201707558},
journal = {Advanced Functional Materials},
number = ,
volume = ,
place = {United States},
year = {Thu May 17 00:00:00 EDT 2018},
month = {Thu May 17 00:00:00 EDT 2018}
}

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