Ionic Liquid-Assisted Crystallization and Defect Passivation for Efficient Perovskite Solar Cells with Enhanced Open-Circuit Voltage.

Perovskite materials have demonstrated many excellent properties in next-generation photovoltaic devices, but the intrinsic defects and the quality of perovskite film still limit the performance and stability of PSCs. Here, 1,3-dimethylimidazolium iodide (DMII) ionic liquid was employed as an additive to passivate the various defects and produce the high-quality perovskite film with enlarged grain sizes. DMII could act as an "ionic stabilizer" for passivating the point defects including the vacancies defects of organic cations and halogen anions of perovskite.

TiO Mesocrystals Processed at Low Temperature as the Electron-Transport Material in Perovskite Solar Cells.

TiO is the most widely used material for preparing the electron-transporting layer (ETL) in perovskite solar cells (PSCs). However, it requires a high-temperature sintering process. Moreover, the intrinsic defects and low electron mobility of TiO ETLs cause instability and hysteresis effects in PSCs.