Enhanced Inorganic CsPbIBr2 Perovskite Film for a Sensitive and Rapid Response Self-Powered Photodetector

Inorganic cesium lead halide CsPbIxBr3–x (x = 0–3) perovskites have recently gained considerable attention as semiconductor materials for the fabrication of photodetectors due to their high thermal and environmental stability. However, preparing high-quality CsPbIxBr3–x perovskite films using a simple spin-coating method is challenging. This study focused on enhancing the performance of a solution-processed all-inorganic CsPbIxBr3–x (x = 1, CsPbIBr2) photodetector using a silver iodide (AgI) additive. Introducing a small amount of AgI into the CsPbIBr2 precursor solution resulted in perovskite films that were more uniform and exhibited compact surface morphology that improved crystallinity and electronic properties. To further explore the influence of the AgI-modified CsPbIBr2 perovskite film on the device performance, we fabricated a self-powered photodetector with the geometry of fluorine-doped tin oxide (FTO)/compact TiO2/CsI(PbBr2)0.99(AgI)0.01/2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (Spiro-OMeTAD)/Au. Photoresponse analysis revealed that the photoresponsivity, on/off ratio, and response time of the CsI(PbBr2)0.99(AgI)0.01 perovskite photodetector were improved. Notably, the CsI(PbBr2)0.99(AgI)0.01 perovskite device showed a higher responsivity and an impressive detectivity of 0.43 A/W and 2.46 × 1011 Jones, respectively, in comparison to the pristine CsPbIBr2 device. This work demonstrates the excellent potential of using inorganic CsI(PbBr2)0.99(AgI)0.01 perovskites in applications for high-performance photodetectors.