High-performance polarization-sensitive photodetectors on two-dimensional <i>β</i>-InSe
Zhinan Guo, Rui Cao, Huide Wang, Xi Zhang, Fanxu Meng, Xue Chen, Siyan Gao, David K. Sang, Thi Huong Nguyen, Anh Tuan Duong, Jinlai Zhao, Y. J. Zeng, Sunglae Cho, Bing Zhao, Ping‐Heng Tan, Han Zhang, Dianyuan Fan
Abstract
Abstract Two-dimensional (2D) indium selenide (InSe) has been widely studied for application in transistors and photodetectors, which benefit from its excellent optoelectronic properties. Among the three specific polytypes (γ-, ϵ- and β-phase) of InSe, only the crystal lattice of InSe in β-phase (β-InSe) belongs to a non-symmetry point group of $D_{6h}^4$, which indicates stronger anisotropic transport behavior and potential in the polarized photodetection of β-InSe-based optoelectronic devices. Therefore, we prepare the stable p-type 2D-layered β-InSe via temperature gradient method. The anisotropic Raman, transport and photoresponse properties of β-InSe have been experimentally and theoretically proven, showing that the β-InSe-based device has a ratio of 3.76 for the maximum to minimum dark current at two orthogonal orientations and a high photocurrent anisotropic ratio of 0.70 at 1 V bias voltage, respectively. The appealing anisotropic properties demonstrated in this work clearly identify β-InSe as a competitive candidate for filter-free polarization-sensitive photodetectors.