Dual-mode visible/UV-blind Sb₂Se₃ photodetector for secure single-pixel imaging

Single-pixel imaging is a natural, secure imaging technique with a code of an imaging algorithm. To enhance security, in this paper, we propose a dual-mode Sb₂Se₃ PD (UV-responsive VIS-blind mode and UV-blind VIS-responsive mode), adding an additional code on the basis of single-pixel imaging. To realize the expected dual-mode, the structure of the PD is designed as Cu/Ag/TiO₂/Sb₂Se₃/ITO/IGO. Thus, the PD on the ITO/IGO side realizes UV blind (254 nm: 4 × 10^-2mA/W, 365 nm: 1.9 × 10^-3mA/W, 395 nm: 6.83 × 10^-2mA/W, white light: 429 mA/W under 0 V). On the other side, due to ZWB1's weak penetration ability of visible light, the PD realizes visible blindness (254 nm: 36 mA/W, 365 nm: 20 mA/W, 395 nm: 12 mA/W, white light: 3.5 × 10^-3mA/W under 0 V). Then, we demonstrate secure single-pixel imaging with the proposed PD and single-pixel imaging. This work may bring an innovative approach to improve the security of cameras and extend the applications of single-pixel imaging and Sb₂Se₃ PDs.