Quasi-Homojunction Based on 1D-Chained Alloyed Sb<sub>2</sub>Se<sub>3</sub> for High-Performance Broadband Photodetection and Matrix Imaging
Ruisi Gao, Xinyi Chen, Xinyue Wang, Hao Hu, Feifan Yang, Ling Lin, Lin Zhou, D Liu, Yanlai Liu, Chang Hu, Jungang He, Shenglin Jiang, Chuanhao Li, Shuo Chen, Guangxing Liang, Guangzu Zhang, Jiang Tang, Kanghua Li
Abstract
Junction-based photodiodes play a crucial role in integrated devices due to their compactness and efficient rectification. However, three-dimensional (3D) semiconductor heterojunctions suffer from high interface defects caused by lattice mismatch, while one-dimensional (1D) semiconductors feature large interchain gaps that alleviate lattice matching requirements and provide high strain relaxation, making them highly promising for homojunction construction. Herein, a quasi-homojunction is constructed via in situ Bi doping in 1D Sb 2 Se 3 . Compared to uniform film photodetectors, the quasi-homojunction-based photodetector exhibits a low dark current (4.8 nA cm –2 ), high light current (62.2 μA cm –2 ), high external quantum efficiency (35.5%@2.73 nW cm –2 ), and fast response speed. Furthermore, the photodetector is monolithically integrated on the thin-film transistor readout circuit for short-wavelength infrared imaging applications, demonstrated in a 64 × 64 pixel array. Moreover, the detectors exhibit a broadband detection from X-ray to near-infrared, showing potential application for image fusion. This work provides a novel strategy for broadband photodetectors and integration.