High Quality Perovskite Crystals for Efficient Film Photodetectors Induced by Hydrolytic Insulating Oxide Substrates

A high quality perovskite film is a key factor in determining the device performance, such as photovoltaic cells, light‐emission diodes, lasers, and photodetectors. Here, a method is presented to improve the crystalline quality of perovskite films on surface‐oxygen‐rich insulating oxide substrates, which can promote the growth of both the polycrystalline and single crystals and enhance the adhesion between the perovskites and the substrates. A much longer carrier diffusion length of exceeding 5 µm together with significantly reduced trap density and nonradiative recombination is achieved for the film. These perovskite films show much better lasing and photodetector performance, indicating promising applications for the light emitting, lasing, and detector devices.