A-Site Substitute for Fabricating All-Inorganic Perovskite CsPbCl₃ with Application in Self-Powered Ultraviolet...

Because of its stable chemical properties and wide band gap, CsPbCl₃ perovskite has shown great application prospects in ultraviolet photodetectors (UPDs). However, the poor solubility of CsCl in organic solvents impedes the fabrication of high-quality CsPbCl₃ films. Herein, we introduced an A-site substitute route for fabricating a high-quality CsPbCl₃ microcrystalline (MC) film by spin-coating cesium acetate on a MAPbCl₃ MC film followed by a high-temperature annealing process. To enhance the device performance of the FTO/SnO₂/CsPbCl₃ MCs/carbon structure UPD, a pressure-assisted annealing strategy was carried out, which reduced the void density and surface roughness of the microcrystal film. Finally, our optimized PDs showed high device performances with an on/off ratio of 6 × 10⁴, a responsivity of 0.13 A W^-1, a detectivity of as high as 1.07 × 10¹² Jones, and a rise/fall time of 10/24 μs. Moreover, our unpacked PDs showed good storage and light stability. Our results lay a foundation for the application of all inorganic perovskite in the ultraviolet region.