Self-powered photodetectors based on CsxDMA1-xPbI3 perovskite films with high detectivity and stability

Metal halide perovskites are widely studied in photodetection applications due to their outstanding optical and electrical properties. However, it is still a challenge to develop self-powered perovskite photodetectors with all the characteristics of high photoresponse performance, broad spectral response range, and excellent long-term stability. Herein, we demonstrate the high-performance self-powered photodetectors based on optimized CsxDMA1-xPbI3 (0.7 < x < 1) perovskite films. By adjusting the solution concentration and molar ratio of CsI/DMAPbI3 in the perovskite precursor, the dark current of devices was decreased significantly by three orders of magnitude and the light current of devices was improved at the same time. Systematic investigations have revealed that the improvement of device performance originates from the reduced bandgap, decreased trap density and increased film thickness of the optimized perovskite films. The optimal self-powered photodetectors display broad spectral response range (300–750 nm), high specific detectivity (>1 × 1013 Jones), fast response, and excellent long-term stability. These intriguing results indicate that CsxDMA1-xPbI3 perovskite films have tremendous application potential in future self-powered photoelectrical detection technology.