Deep-ultraviolet photodetector based on pulsed-laser-deposited Cs₃Cu₂I₅ films/n-Si heterojunction

All-inorganic lead-free perovskite Cs₃Cu₂I₅ thin films were prepared using pulsed laser deposition. Effects of the substrate temperature, laser energy, and laser frequency on the film structure and optoelectronic properties were studied. A heterojunction photodetector based on Cs₃Cu₂I₅/n-Si was constructed, and the deep-ultraviolet photoresponse was obtained. A high I/I ratio of 130 was achieved at -1.3V, and the peak response of the heterojunction photodetector was 70.8 mA/W (280 nm), with the corresponding specific detectivity of 9.44×10¹¹cm⋅Hz^1/2⋅W^-1. Moreover, the device showed good stability after being exposed to air for 30 days.