The surface oxidation effect on photocurrent in WSe1.95Te0.05 nanosheets

Shiu-Ming Huang; Tzu-Yueh Tu; Pin-Cing Wang; Mitch Chou; Chang-Yu Li; Hao-Ting Wu; Yue-Cheng Hsieh; Ruei-San Chen

doi:10.1016/j.isci.2024.111461

The surface oxidation effect on photocurrent in WSe_1.95Te_0.05 nanosheets

iScience. 2024 Nov 22;27(12):111461. doi: 10.1016/j.isci.2024.111461. eCollection 2024 Dec 20.

Authors

Shiu-Ming Huang¹, Tzu-Yueh Tu¹, Pin-Cing Wang¹, Mitch Chou², Chang-Yu Li³, Hao-Ting Wu⁴, Yue-Cheng Hsieh⁴, Ruei-San Chen⁴

Affiliations

¹ Department of Physics, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
² Center of Crystal Research, Academy of Innovative Semiconductor and Sustainable Manufacturing, National Cheng-Kung University, Tainan 70101, Taiwan.
³ Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan.
⁴ Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.

Abstract

Surface oxidation effect on photocurrent responsibility was detected in WSe_1.95Te_0.05 nanosheets, and the photocurrent response depends on the light wavelength. It is enhanced at the wavelength of 405 nm, while showing no change at the wavelength of 532 nm and suppressed at the wavelength of 808 nm. The incident photon-to-current efficiency (IPCE) is expected to increase at 405 nm wavelength, remain unchanged at 532 nm wavelength, and decrease at 808 nm wavelength. Therefore, WO₃ contributes to the intrinsic properties. The trend of photocurrent change after half-year exposure corresponds to the absorbance change from pristine WSe_1.95Te_0.05 to WO₃. The wavelength-dependent photocurrent responsibility is understood as the wavelength-dependent IPCE of WO₃ that is from the surface-oxidized WSe_1.95Te_0.05.

Keywords: Chemistry; Materials science; Physics.