Thermal assisted blade coating methylammonium lead iodide films with non-toxic solvent precursors for efficient perovskite solar cells and sub-module

Atmospheric thermal assisted blade coating (TABC) method, which is quick film crystallization and easier fabrication than the commonly used spin-coating process, to prepare a high quality CH₃NH₃PbI₃ perovskite film is investigated in this work. Selection of the perovskite precursor solvents and controlling the ratio of the mixed solvent as well as substrate temperature for perovskite film formation are important factors in this TABC process. Based on the results obtained in this work, substrate temperature is the key factor for managing the perovskite film phase transition which influences the film roughness and crystallinity. Furthermore, the high-quality perovskite films are prepared by perovskite precursors with mixture of solvents containing GBL/DMSO at the ratio from 1/9 to 5/5. By using the optimum substrate temperature of 130 °C and the GBL/DMSO solvent ratio of 1/9 (G01D09) for the preparation of small area n-i-p and p-i-n PSCs as well as the p-i-n type perovskite sub-module, the power conversion efficiencies of 17.55%, 16.90% and 13.03%, respectively, are acquired under the illumination of 100 mW/cm² (AM 1.5G).