Enhanced Photoresponsive Properties of Perovskite Films on Metal Oxide LaAlO₃ Substrates

Abstract

We report enhanced photoresponsive properties of planar-type perovskite films fabricated by spin-coating method on metal oxide LaAlO3 substrates. The reliable Ilight/Idark ratio (>104), responsivity (70 mA/W), detectivity (1.5 × 1010 Jones), and photoresponsive time (0.26 ms) of films on LaAlO3 substrates are achieved. These results are caused by the abundant La vacancies at the surface of LaAlO3 substrates after the plasma treatment, which would form the build-in electric field at the interface and meanwhile induce the sub-band gap photoluminescence. Thus, the photon-generated carrier separation and density are increased. Our results pave a way for promoting photoresponsive properties by the interface effect and create an opportunity for future high-performance photodetectors based on perovskites.