Ethylammonium as an alternative cation for efficient perovskite solar cells from first-principles calculations

Diwen Liu; Qiaohong Li; Kechen Wu

doi:10.1039/c9ra00853e

Ethylammonium as an alternative cation for efficient perovskite solar cells from first-principles calculations

RSC Adv. 2019 Mar 6;9(13):7356-7361. doi: 10.1039/c9ra00853e. eCollection 2019 Mar 1.

Authors

Diwen Liu^{1

2}, Qiaohong Li¹, Kechen Wu^{1

3}

Affiliations

¹ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences Fuzhou 350002 P. R. China lqh2382@fjirsm.ac.cn wkc@fjirsm.ac.cn +86 591 63173138.
² University of Chinese Academy of Sciences Beijing 100049 P. R. China.
³ Center for Advanced Marine Materials and Smart Sensors, Minjiang University Fuzhou 350108 P. R. China.

Abstract

Mixed-cation lead halide perovskites have emerged as a new class of promising photovoltaic materials for perovskite solar cells. Formamidinium (FA), methylammonium (MA), and Cs cations are widely studied in the field of mixed-cation hybrid halide perovskites. In this work, we have investigated ethylammonium (CH₃CH₂NH₃, EA) as an alternative cation to explore the stabilities and electronic properties of mixed MA_1-x EA _x PbI₃ perovskites. The results indicate that replacing MA with EA is a more effective way to improve the stabilities of the mixed MA_1-x EA _x PbI₃ perovskites except for MA_0.75EA_0.25PbI₃. The band gap of MA_1-x EA _x PbI₃ slightly increases with x from 0.25 to 1.00, which is quite different from the MA-FA mixed-cation perovskites. The results indicate that the c axis distortion of the Pb-I-Pb bond angles can play a greater role in tuning the band gap. Moreover, the mixed MA_1-x EA _x PbI₃ perovskites show comparable absorption abilities in the visible light region to the pure MAPbI₃ structure. We hope that our study will be greatly helpful for further experiments to find more efficient perovskite materials in the future.