Cesium Acetate-Induced Interfacial Compositional Change and Graded Band Level in MAPbI3 Perovskite Solar Cells

Ajay Kumar Jena; Ayumi Ishii; Zhanglin Guo; Muhammad Akmal Kamarudin; Shuzi Hayase; Tsutomu Miyasaka

doi:10.1021/acsami.0c06315

Cesium Acetate-Induced Interfacial Compositional Change and Graded Band Level in MAPbI₃ Perovskite Solar Cells

ACS Appl Mater Interfaces. 2020 Jul 29;12(30):33631-33637. doi: 10.1021/acsami.0c06315. Epub 2020 Jul 17.

Authors

Ajay Kumar Jena¹, Ayumi Ishii¹, Zhanglin Guo¹, Muhammad Akmal Kamarudin², Shuzi Hayase², Tsutomu Miyasaka¹

Affiliations

¹ Toin University of Yokohama, 1614 Kurogane-cho, Aoba, Yokohama 225-8503, Japan.
² The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu 182-8585, Tokyo.

PMID: 32628004
DOI: 10.1021/acsami.0c06315

Abstract

Compositional engineering and interfacial modifications have played pivotal roles in the accomplishment of high-efficiency perovskite solar cells (PSCs). Different interfaces in the PSCs influence the performance remarkably either by altering the crystallization of the active material or shifting the energy levels or improving the electrical contact. This work reports how a thin layer of cesium acetate on the TiO₂ electron transport layer (ETL) induces generation of a PbI₂-rich methylammonium lead iodide (MAPbI₃) composition at the ETL/MAPbI₃ interface, which downshifts the conduction band level of MAPbI₃ to create an energy level gradient favorable for carrier collection, resulting in higher photocurrent, fill factor, and overall power conversion efficiency.

Keywords: PbI2-rich MAPbI3 interface; band alignment; cesium acetate treatment; interfacial composition; interfacial modification; perovskite solar cell.