Highly-Sensitive, Flexible, and Self-Powered UV Photodetectors Based on Perovskites Cs₃Cu₂I₅/ PEDOT: PSS Heterostructure

Herein, we demonstrate a highly-sensitive, flexible, and self-powered UV photodetector based on perovskites Cs3Cu2I5/PEDOT: PSS heterostructure. The device shows a high photoresponsivity ( ${R}$ ) of 170.3 mA/W, on/off ratio of $5.7\times 10^{{3}}$ , response/recovery time of 177.0/ $195.2 \mu \text{s}$ , and good specific detectivity ( ${D}^{\ast }$ ) of $1.0\times 10^{{13}}$ Jones to 275 nm light at self-powered mode. Benefiting from the solvent vapor annealing process, the Cs3Cu2I5 film is conformally attached to the flexible substrate and maintains relatively high performance at a curvature radius of 3 mm. Our work could pave the way to open up high-performance self-powered perovskites UV photodetector in flexible solution-based optoelectronics.