Inorganic cesium lead halide CsPbI x Br3–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 CsPbI x Br3–x perovskite films using a simple spin-coating method is challenging. This study focused on enhancing the performance of a solution-processed all-inorganic CsPbI x Br3–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.

Self-powered photodetectors (PDs) are suitable for application in smart systems, image sensing and optical communications. Herein, a self-powered PD based on triple cation lead-halide perovskite (TCLP) is reported. We showed the effect of bromide concentration on the optical and structural properties of the TCLP films. Additionally, an environmental stability test was conducted and it was found that TCLP with 10% Br can remain stable for up to 128 days after exposure to ambient air. Using this material, a self-powered perovskite PD was fabricated and demonstrated an impressive performance with a responsivity of 0.52 A W −1 , detectivity of 8.8×10 12 Jones, on/off ratio of 7.3×10 5 , and a rapid rise and decay time of 19 μs and 21 μs, respectively. This work offers a useful insight into the effects the fabrication method of the thin film plays in building low-cost, stable, and high-performance self-powered PDs for application in structural health monitoring, imaging, optical communication, and biomedical sensing.