Role of organic cation orientation in formamidine based perovskite materials

Siyu Liu; Jing Wang; Zhe Hu; Zhongtao Duan; Hao Zhang; Wanlu Zhang; Ruiqian Guo; Fengxian Xie

doi:10.1038/s41598-021-99621-1

Role of organic cation orientation in formamidine based perovskite materials

Sci Rep. 2021 Oct 14;11(1):20433. doi: 10.1038/s41598-021-99621-1.

Authors

Siyu Liu¹, Jing Wang², Zhe Hu², Zhongtao Duan¹, Hao Zhang³, Wanlu Zhang², Ruiqian Guo^{4

5}, Fengxian Xie^{6

7}

Affiliations

¹ Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China.
² Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China.
³ Department of Optical Science and Engineering, Fudan University, Shanghai, 200433, China.
⁴ Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China. [email protected].
⁵ Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China. [email protected].
⁶ Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai, 200433, China. [email protected].
⁷ Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai, 200433, China. [email protected].

Abstract

The rotation of organic cations is considered to be an important reason for the dynamic changes in stability and photoelectric properties of organic perovskites. However, the specific effect of organic cations rotation on formamidine based perovskite is still unknown. In our work, first-principles calculations based on density functional theory are used to examine the effect of the rotation of formamidine cations in FAPbI₃ and FA_0.875Cs_0.125PbI₃. We have comprehensively calculated the structure, electronic and optical properties of them. We found a coupling effect between formamidine cations rotation and cesium atom. This coupling effect changes the inclination angle of octahedron to regulate electron distribution, band gaps, and optical absorption. Hence, changing the cation orientation and substitution atom is a feasible way to dynamically adjust the energy band, dielectric constant and absorption edge of perovskite. Preparing perovskite with tunable properties is just around the corner through this way.

Abstract

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