Low-temperature fabrication of lead-free Ag2BiI5 perovskite photodetector with excellent weak light detection ability for accurate gesture recognition

Abstract

In recent years, lead halide perovskites have been extensively researched in the optoelectronics field due to their excellent optical and electrical properties, while the inherent toxicity and instability of lead halide perovskites have hindered their commercialization. Stable, lead-free perovskites as a substitute of the Pb-based perovskites show great attention. Herein, the green antisolvent diethyl carbonate is introduced to realize the low-temperature fabrication of nontoxic perovskite AgBiI. The AgBiI perovskite photodetector (PD) shows excellent performance with a detectivity of as high as 1.13 × 10 Jones and a linear dynamic range (LDR) of 147 dB. Besides, the weak light with the light intensity of as low as 18.3 nW/cm can be detected by our PD. Moreover, the flexible PDs are also prepared with this low-temperature process, which shows good device performance with stable bending resistance characteristics. Based on the excellent optoelectronic properties of the AgBiI PDs, a gesture recognition system is built which can realize rapid and accurate gesture recognition under ordinary indoor light, with an accuracy of 98.35 %. Our research provides new insights for the development and application of green and environmentally friendly perovskite PD.