Dissociation of Methylammonium Cations in Hybrid Organic–Inorganic Perovskite Solar Cells

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• 作者：Weidong Xu ; Lijia Liu ; Linju Yang ; Pengfei Shen ; Baoquan Sun ; John A. McLeod
• 刊名：Nano Letters
• 出版年：2016
• 出版时间：July 13, 2016
• 年：2016
• 卷：16
• 期：7
• 页码：4720-4725
• 全文大小：449K
• 年卷期：0
• ISSN：1530-6992

文摘

Organic–inorganic lead perovskites have shown great promise as photovoltaic materials, and within this class of materials (CH₃NH₃)PbI_3–xCl_x is of particular interest. Herein we use soft X-ray spectroscopy and density functional theory calculations to demonstrate that the methylammonium cations in a typical photovoltaic layer may dissociate into a metastable arrangement of CH₃I–Pb₂ defects and trapped NH₃. The possibility that other metastable configurations of the organic components in (CH₃NH₃)PbI_3–xCl_x is rarely considered but adds an entirely new dimension in understanding the charge trapping, ionic transport, and structural degradation mechanisms in these materials. Understanding the influence of these other configurations is of critical importance for further improving the performance of these photovoltaics.