Self-powered, flexible and room temperature operated solution processed hybrid metal halide p-type sensing element for efficient hydrogen detection

Hydrogen (H-2) is a well-known reduction gas and for safety reasons is very important to be detected. The most common systems employed along its detection are metal oxide-based elements. However, the latter demand complex and expensive manufacturing techniques, while they also need high temperatures or UV light to operate effectively. In this work, we first report a solution processed hybrid mixed halide spin coated perovskite films (CH3NH3PbI3-xClx) that have been successfully applied as portable, flexible, self-powered, fast and sensitive hydrogen sensing elements, operating at room temperature. The minimum concentrations of H-2 gas that could be detected was down to 10 ppm. This work provides a new pathway on gases interaction with perovskite materials, poses new questions that must be addressed regarding the sensing mechanisms involved. The utilization of halide perovskite sensing elements demonstrates their potential beyond solar cell applications.