Poly(methyl methacrylate) embedded perovskite films for improving solar cell performance

•A void-passivated transparent perovskite films were prepared by utilizing a PMMA as a framework for crystal growth.•The semitransparent perovskite film is prepared from PbICl layer assisting sequential inter-diffusion process.•The perovskite film based photovoltaic device with PMMA presents 15.46% efficiency with less hysteresis.