Chun-Yan Wu,* Kai-Jun Cao, Yu-Xuan Le, Jing-Yue Li, Chen-Yue Zhu, Li Wang, Yu-Xue Zhou, Di Wu, Lin-Bao Luo*

Abstract:In this work, we report on the synthesis of InSe nanobelts through a catalyst-free chemical vapor deposition (CVD) growth approach. A remarkable blue shift of the peak photoresponse was observed when the thickness of InSe nanobelt decreases from 562 to 165 nm. Silvaco Technology Computer Aided Design (TCAD) simulation reveals that such a shift in spectral response should be ascribed to the wavelength-dependent absorption coefficient of InSe, for which incident light with shorter wavelengths will be absorbed near the surface, while light with longer wavelengths will have a larger penetration depth, leading to a red shift of the absorption edge for thicker nanobelt device. Based on the above theory, three kinds of photodetectors sensitive to blue (450 nm), green (530 nm) and red (660 nm) incident light were achieved by tailoring the thickness of the nanobelt, which can enable the spectral reconstruction of a purple “H” pattern, suggesting the potential application of 2D layered semiconductors in the full-color imaging.