Large Surface Photovoltage of WS2/MoS2 and MoS2/WS2 Vertical Hetero-bilayers
- 주제(키워드) surface photovoltage , MoS2 , WS2 , hetero-bilayer , open-circuit voltage
- 주제(기타) Engineering, Electrical & Electronic
- 주제(기타) Materials Science, Multidisciplinary
- 설명문(일반) [Kim, Bora; Kim, Jayeong; Choi, Hyeji; Yoon, Seokhyun; Kim, Dong-Wook] Ewha Womans Univ, Dept Phys, Seoul 03760, South Korea; [Tsai, Po-Cheng; Lin, Shih-Yen] Acad Sinica, Res Ctr Appl Sci, Taipei 11529, Taiwan; [Tsai, Po-Cheng; Lin, Shih-Yen] Natl Taiwan Univ, Grad Inst Elect Engn, Taipei 10617, Taiwan
- 등재 SCIE, SCOPUS
- 발행기관 AMER CHEMICAL SOC
- 발행년도 2021
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000182212
- 본문언어 영어
- Published As http://dx.doi.org/10.1021/acsaelm.1c00192
초록/요약
Hetero-bilayers, composed of transition metal dichalcogenide (TMD) monolayers of MoS2(1L-MoS2) and 1L-WS2, are grown on Al2O3 substrates through sulfurization of predeposited metal thin films. A very smooth surface morphology and the uniform contact potential difference (CPD) maps show that high-quality homogeneous TMD layers are obtained. The light-induced CPD change, that is, surface photovoltage (SPV), of the samples is investigated. A record high SPV is measured under 532 nm illumination with a power density of 13 mW/cm(2) from the hetero-bilayers, with values of 800 mV for 1L-WS2/1L-MoS2 and -790 mV for 1L-MoS2/1L-WS2. Band diagrams are proposed to explain the observed CPD and SPV characteristics. The power dependence of the SPV demonstrates that the measured values represent the expected open-circuit voltage of the hetero-bilayers. The obtained results suggest that optimal growth and proper contact formation with the TMD vertical hetero-bilayers will enable high-efficiency ultrathin photovoltaic devices.
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