Microwave application to efficient annealing process of CH3NH3PbI3 perovskite crystalline films

Abstract

As next-generation printable solar cells, perovskite solar cell utilizing organometal halide perovskite crystalline semiconductor as the active layer has been considered as one of the most promising systems for its high efficiency (> ∼22%) and construction with low-cost materials. Annealing process of organometal halide perovskite crystalline films are, however, relatively time-consuming process for the perovskite solar cells. We propose the microwave heating applied to the annealing process of the CH3NH3PbI3 perovskite crystalline films for converting the intermediate state of as-coated precursor films into perovskite poly-crystalline films. Observed rapid conversion process into perovskite crystals with higher crystallinity and even the degradation of perovskite to be PbI2 by evaporation of methylammonium iodide at relatively lower temperature to the conventional hotplate heating imply a promising potential to achieve novel high throughput annealing process with high-quality crystallinity of perovskite films at low-temperature due to direct and effective heating of CH3NH3PbI3 films by the microwave irradiation.