WS2 film on a SiC substrate and its optical properties

Abstract

Photoelectric functional material WS2 thin film on SiC substrate was synthesized. Both 15 and 150 nm thickness of WS2 film were deposited on an n-doped SiC substrate (7.37 x 10(19) cm(-3)) by pulsed laser deposition method. Optical properties of the WS2/SiC material were discovered. (I) a photovoltaic effect: (1) there is a cutoff wavelength lambda(c) (661 nm), which means the wavelength of an incident monochromatic light must be less than lambda(c) in order to have the photovoltaic effect; (2) the incident light must be polarized. (3) It was found that the maximum open circuit voltage output is 6.3 V in a condition of 40 mW @ 532 nm. (II) Wavelength blueshift: when a laser of 532 nm is used in the experiment to incident perpendicularly through the thin layer WS2/SiC film stack, which is driven by an external electric field, it is found that the 532-nm photons are blueshifted 1.33 nm under a 30 V (DC) voltage. We also find that the blueshift of the laser wavelength is tunable with the applied voltage. Inverse Compton scattering of the photon by both electron and hole is used to explain this blueshift, the consistency of experimental results and the theoretical calculation for the wavelength blueshift was found. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.