题目：

Unraveling the Surface State of Photovoltaic Perovskite Thin Film

作者：

Rui Wang,^1,# Jingjing Xue,^1,# Xihan Chen,^2,# Canglang Yao,³ Zhao-Kui Wang,^1,5,* Marc H. Weber,⁴ Aaron H. Rose,² Selbi Nuryyeva,¹ Jiahui Zhu,¹ Tianyi Huang,¹ Yepin Zhao,¹ Shaun Tan,¹ Matthew C. Beard,² Yanfa Yan,^3,* Kai Zhu,^2,* and Yang Yang ^1,*

单位：

¹Department of Materials Science and Engineering and California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA 90095, USA.

²National Renewable Energy Laboratory, Golden, CO 80401, USA.

³Department of Physics and Astronomy and Center for Photovoltaics Innovation and Commercialization, The University of Toledo, Toledo, OH 43606, USA.

⁴Centerfor Materials Research, Washington State University, Pullman, WA 99164, USA.

⁵Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou 215123, China.

摘要：

Recently, most of the highly efficient perovskite optoelectronic devices have been reported to employ effective surface passivation strategies, further confirming the significance of surface states in regulating their device performance. Therefore, an in-depth understanding and a systematic approach toward comprehensive investigations on perovskite surface states are urgently required. Here, we present methodical studies toward understanding the surface states in perovskite thin films utilizing a molecular ‘‘positively charged defect indicator’’ strategy. In formamidinium (FA)-methylammonium (MA) mixed-cation perovskite thin films, a nonuniform distribution of cations is uncovered with FA cations being close to the top and MA close to the bottom of the film, which leads to unique sur- face defect energetics. Antisite FA_I was found to become a dominant deep trap on the surface of this system. As a result, a surface recombination velocity as low as 20 cm/s was achieved in such FA-based perovskite photovoltaic devices.

影响因子：

暂无

分区情况：

暂无

链接：

https://doi.org/10.1016/j.matt.2021.04.024