CsPbCl₃-Driven Low-Trap-Density Perovskite Grain Growth for >20% Solar Cell Efficiency.

ABSTRACT: Charge recombination in grain boundaries is a significant loss mechanism for perovskite (PVK) solar cells. Here, a new strategy is demonstrated to effectively passivate trap states at the grain boundaries. By introducing a thin layer of CsPbCl₃ coating before the PVK deposition, a passivating layer of PbI₂ is formed at the grain boundaries. It is found that at elevated temperature, Cl^- ions in the CsPbCl₃ may migrate into the PVK via grain boundaries, reacting with MA⁺ to form volatile MACl and leaving a surface layer of PbI₂ at the grain boundary. Further study confirms that there is indeed a small amount of PbI₂ distributed throughout the grain boundaries, resulting in increased photoluminescence intensity, incr

SUBMITTER: Jiang J 

PROVIDER: S-EPMC6051377 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature