Graduate School of Engineering, Toin University of Yokohama , 1614 Kurogane-cho, Aoba, Yokohama, Kanagawa 225-8503, Japan.
Faculty of Science and Engineering, Sophia University , Chiyoda-ku, Tokyo 102-8554, Japan.
ACS Appl Mater Interfaces. 2017 Jun 7;9(22):18739-18747. doi: 10.1021/acsami.7b02924. Epub 2017 May 23.
We developed a new and simple solvent vapor-assisted thermal annealing (VA) procedure which can reduce grain boundaries in a perovskite film for fabricating highly efficient perovskite solar cells (PSCs). By recycling of solvent molecules evaporated from an as-prepared perovskite film as a VA vapor source, named the pot-roast VA (PR-VA) method, finely controlled and reproducible device fabrication was achieved for formamidinium (FA) and methylammonium (MA) mixed cation-halide perovskite (FAPbI)(MAPbBr). The mixed perovskite was crystallized on a low-temperature prepared brookite TiO mesoporous scaffold. When exposed to very dilute solvent vapor, small grains in the perovskite film gradually unified into large grains, resulting in grain boundaries which were highly reduced and improvement of photovoltaic performance in PSC. PR-VA-treated large grain perovskite absorbers exhibited stable photocurrent-voltage performance with high fill factor and suppressed hysteresis, achieving the best conversion efficiency of 18.5% for a 5 × 5 mm device and 15.2% for a 1.0 × 1.0 cm device.
我们开发了一种新的、简单的溶剂蒸汽辅助热退火（VA）程序，可以减少钙钛矿薄膜中的晶界，从而制备高效的钙钛矿太阳能电池（PSCs）。通过回收从预先制备的钙钛矿薄膜中蒸发的溶剂分子作为 VA 蒸汽源，即“锅烤 VA（PR-VA）方法”，可以实现对甲脒（FA）和甲铵（MA）混合阳离子卤化物钙钛矿（FAPbI）（MAPbBr）的精细控制和可重复的器件制造。混合钙钛矿在低温制备的锐钛矿 TiO 介孔支架上结晶。当暴露于非常稀的溶剂蒸汽中时，钙钛矿薄膜中的小晶粒逐渐统一成大晶粒，导致晶界高度减少，并提高了 PSC 的光伏性能。PR-VA 处理的大晶粒钙钛矿吸收剂表现出稳定的光电电流-电压性能，具有高填充因子和抑制迟滞，在 5×5mm 器件中实现了最佳的转换效率为 18.5%，在 1.0×1.0cm 器件中实现了 15.2%。
