High‐Performance Rb–Cs0.14FA0.86Pb(BrxI1−x)3 Perovskite Solar Cells Achieved by Regulating the Halogen Exchange in Vapor–Solid Reaction Process. Issue 5 (31st March 2021)

• Record Type: Journal Article
• Authors: Niu, Cheng; Wang, Chang; Zhang, Gaojie; Zhao, Qianqian; Fang, Cheng; Li, Wangnan; Huang, Fuzhi; Ku, Zhiliang; Cheng, Yi-bing
• Is Part Of: Solar RRL. Volume 5:Issue 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-03-31
• Subjects: halogen exchanges -- perovskite solar cells -- vapor–solid reaction; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202100102
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : Despite tremendous progress in efficiency and stability, perovskite solar cells are still facing the challenge of scalability and reproducibility. Vapor–solid reaction methods that derived from the chemical vapor deposition have been regarded as facile approaches to prepare perovskite films with large size. However, different from the precise control of compounding ratio by weighting in the solution process, the perovskite films deposited by vapor–solid reaction methods always suffer from undesired I − /Br − ratio, leading to poor performance of the solar device. Thus, controllable halogen exchange in the vapor–solid reaction process is significant for the further development of this technique. Herein, different alkali‐metal ions (such as Na +, K +, and Rb + ) are added into the inorganic CsBr/PbI2 framework, and it is found that the halogen exchange in the vapor–solid reaction process can be regulated by these ions. After optimization, high‐quality Rb‐Cs0.14 FA0.86 Pb(Br x I1‐ x )3 films with proper I − /Br − ratio are successfully obtained. Perovskite solar cells based on the as‐prepared perovskite films exhibit a significant enhancement on V oc and the champion power conversion efficiency reaches 19.6% with a V oc of 1.13 V. Abstract : Alkali‐metal ions including Na +, K + and Rb + are used to manipulate Br − /Cl − exchange in the vapor‐solid reaction process. With moderate RbI in the CsBr/PbI2 film, high‐quality perovskite films with large grain size and low trap density can be obtained. The as‐prepared PSCs exhibits a significant enhancement in V oc and achieves a champion power conversion efficiency of 19.6%.