Organolead halide perovskite-based metal-oxide-semiconductor structure photodetectors achieving ultrahigh detectivity

Abstract

Organolead halide perovskite with excellent optoelectronic properties, which endows its potential applications in versatile optoelectronic device including solar cells and photodetectors. In spite of great efforts made on the perovskite photodetectors, novel device configurations based on perovskite films have to be explored to further improve the performance. Here, we present perovskite photodetectors enabled by a novel metal (Al)–oxide–semiconductor (perovskite) (MOS) structure. The unique photodetector can work on a wide voltage range and exhibits extreme characteristics with a pA-scale dark current, and a high detectivity (>1014 Jones). Both ultralow dark and light currents enable the small power consumption output ∼nW under 2 mW cm−2 at 2 V. The C–V data analysis proves that the charge carriers are accumulated at the oxide/perovskite interface, which leads to the reduction of the conduct band offset. At a low voltage the current transport behaviors for the MOS structure photodetectors are dominated by the Ohm’s Law, while at a high voltage, the main mechanism is Schottky emission which is demonstrated by temperature-dependence I–V measurements. Our results strongly propose the use of perovskite based photodetectors with a unique MOS structure in the application of optoelectronic devices.