Quasi-Homojunction Based on 1D-Chained Alloyed Sb₂Se₃ for High-Performance Broadband Photodetection and Matrix...

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 Sb₂Se₃. 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.