期刊
JOURNAL OF PHYSICAL CHEMISTRY C
卷 122, 期 23, 页码 12140-12147出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.jpcc.8b00631
关键词
-
资金
- Carl Zeiss Foundation
- Federal Ministry of Education and Research (BMBF)
Despite the intense research effort on metal halide perovskites, the fundamental correlation between the crystal structure and optoelectronic properties remains unclear. As many intriguing phenomena are expected to be based on the dipolar character of the rotating organic cations, an improved understanding of the material's polarizability is of high relevance. Here, we study the orthorhombic-etragonal phase transition of methylammonium lead iodide to gain insight into the polarization mechanism at low temperatures and the resulting effects on solar cell performances. Using thermally stimulated current measurements, we detect polarization currents when cooling or heating across the phase transition. These (de)polarization currents are found to correlate with a sudden change in rotational freedom of the organic cations, with a temperature range of 20 K separating polarizing and depolarizing processes. The nature of this cation polarization within the orthorhombic phase is investigated with respect to its intrinsic and extrinsic polarizability. Although the amount of unamplified polarization is determined to be only in the order of a few nC/cm(2), our results show significant increases in solar cell performances upon polarization, highlighting the intimate relationship between the alignment of organic cations and optoelectronic properties in metal halide perovskites.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据