Highly Uniform Large-Area (100 cm2) Perovskite CH3NH3PbI3 Thin-Films Prepared by Single-Source Thermal Evaporation

In this work, we report the reproducible preparation method of highly uniform large-area perovskite CH3NH3PbI3 thin films by scalable single-source thermal evaporation with the area of 100 cm(2). The microstructural and optical properties of large-area CH3NH3PbI3 thin films were investigated. The dense, uniform, smooth, high crystallinity of large-area perovskite thin film was obtained. The element ratio of Pb/I was close to the ideal stoichiometric ratio of CH3NH3PbI3 thin film. These films show a favorable bandgap of 1.58 eV, long and balanced carrier-diffusion lengths. The CH3NH3PbI3 thin film perovskite solar cell shows a stable efficiency of 7.73% with almost no hysteresis, indicating a single-source thermal evaporation that is suitable for a large area perovskite solar cell.