A broad-spectral-response perovskite photodetector with a high on/off ratio and high detectivity

Abstract

Given their high photoconversion efficiency, organometal halide perovskites have attracted much interest in ultraviolet-visible-near infrared photodetectors (PDs). However, recombination of carriers in perovskites, which leads to low photocurrent, has always been an adverse factor for device performance. Here, we demonstrate a way to overcome this problem by incorporating technologically-mature Si. Meanwhile, the dark current of the device can be maintained at a low level after inserting a TiO₂ layer between the CH₃NH₃PbI₃ film and the Si substrate. The fabricated CH₃NH₃PbI₃/TiO₂/Si tri-component PD displays a high on/off ratio of 6 × 10³ and a high detectivity of 4.85 × 10¹³ Jones. In addition, the PD shows broad photoresponse with a long cut-off wavelength of 1100 nm. The design here provides an intriguing way for improving perovskite-based PDs.