2D Materials and Heterostructures for Electronic, Optoelectronic, and Thermoelectric Device Applications
Invited
Abstract
In this talk, I will review our recent progress in the area of 2D materials and heterostructures. We have demonstrated several approaches for converting many-layer transition metal dichalcogenides (TMDs) from indirect to direct band gap semiconductors using radiation exposure and plasma treatment techniques through an inter-layer decoupling mechanism.1-3 In addition to converting the band structure of these materials, these material processing techniques result in substantial reduction in unintentional doping and improved charge neutrality,4 as well as strong circularly polarized photoluminescence.5 We have also investigated cross-plane transport in vertically-stacked 2D materials, including graphene/BN and graphene/MoS2 heterostructures, for applications is thermoelectric and thermionic energy conversion,6, 7 as well as photodiodes.8
1. Dhall, et al., Direct Bandgap Transition in Many-Layer MoS2 by Plasma-Induced Layer Decoupling. Advanced Materials, 27, 1573 (2015).
2. Wang, et al., Radiation-induced direct bandgap transition in few-layer MoS2. Applied Physics Letters, DOI:10.1063/1.5005121 (2017).
3. Li, et al., Layer Control of WSe2 via Selective Surface Layer Oxidation. ACS Nano, 10, 6836-6842 (2016).
4. Dhall, et al., Charge neutral MoS2 field effect transistors through oxygen plasma treatment. Journal of Applied Physics, 120, 195702 (2016).
5. Dhall, et al., Strong Circularly Polarized Photoluminescence from Multilayer MoS2 Through Plasma Driven Direct-Gap Transition. Acs Photonics, 3, 310-314 (2016).
6. Li, et al., Cross-Plane Seebeck Coefficient Measurement of Misfit Layered Compounds (SnSe)(n)(TiSe2)(n), (n=1,3,4,5). Nano Letters, 17, 1978-1986 (2017).
7. Poudel, et al., Cross-plane Thermoelectric and Thermionic Transport across Au/h-BN/Graphene Heterostructures. Scientific Reports, DOI:10.1038/s41598-017-12704-w (2017).
8. Li, et al., Highly efficient, high speed vertical photodiodes based on fewlayer MoS2. 2D Materials, 4, 015003 (2016).
1. Dhall, et al., Direct Bandgap Transition in Many-Layer MoS2 by Plasma-Induced Layer Decoupling. Advanced Materials, 27, 1573 (2015).
2. Wang, et al., Radiation-induced direct bandgap transition in few-layer MoS2. Applied Physics Letters, DOI:10.1063/1.5005121 (2017).
3. Li, et al., Layer Control of WSe2 via Selective Surface Layer Oxidation. ACS Nano, 10, 6836-6842 (2016).
4. Dhall, et al., Charge neutral MoS2 field effect transistors through oxygen plasma treatment. Journal of Applied Physics, 120, 195702 (2016).
5. Dhall, et al., Strong Circularly Polarized Photoluminescence from Multilayer MoS2 Through Plasma Driven Direct-Gap Transition. Acs Photonics, 3, 310-314 (2016).
6. Li, et al., Cross-Plane Seebeck Coefficient Measurement of Misfit Layered Compounds (SnSe)(n)(TiSe2)(n), (n=1,3,4,5). Nano Letters, 17, 1978-1986 (2017).
7. Poudel, et al., Cross-plane Thermoelectric and Thermionic Transport across Au/h-BN/Graphene Heterostructures. Scientific Reports, DOI:10.1038/s41598-017-12704-w (2017).
8. Li, et al., Highly efficient, high speed vertical photodiodes based on fewlayer MoS2. 2D Materials, 4, 015003 (2016).
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Presenters
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Steve Cronin
CEMMA, Univ of Southern California, Univ of Southern California, Electrical Engineering - Electrophysics, University of Southern California, University of Southern California
Authors
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Steve Cronin
CEMMA, Univ of Southern California, Univ of Southern California, Electrical Engineering - Electrophysics, University of Southern California, University of Southern California