Functionality-Directed Screening of Pb-Free Hybrid Organic–Inorganic Perovskites with Desired Intrinsic Photovoltaic Functionalities

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• 作者：Dongwen Yang ; Jian Lv ; Xingang Zhao ; Qiaoling Xu ; Yuhao Fu ; Yiqiang Zhan ; Alex Zunger ; Lijun Zhang
• 刊名：Chemistry of Materials
• 出版年：2017
• 出版时间：January 24, 2017
• 年：2017
• 卷：29
• 期：2
• 页码：524-538
• 全文大小：843K
• ISSN：1520-5002

文摘

The material class of hybrid organic–inorganic perovskites has risen rapidly from a virtually unknown material in photovoltaic applications a short 7 years ago into an ∼20% efficient thin-film solar cell material. As promising as this class of materials is, however, there are limitations associated with its poor long-term stability, nonoptimal band gap, presence of environmentally toxic Pb element, etc. We herein apply a functionality-directed theoretical materials selection approach as a filter for initial screening of the compounds that satisfy the desired intrinsic photovoltaic functionalities and might overcome the above limitations. First-principles calculations are employed to systemically study thermodynamic stability and photovoltaic-related properties of hundreds of candidate hybrid perovskites. We have identified in this materials selection process 14 Ge- and Sn-based materials with potential superior bulk-material-intrinsic photovoltaic performance. A distinct class of compounds containing NH₃COH⁺ with the organic molecule derived states intriguingly emerging at band-edges is found. Comparison of various candidate materials offers insights on how composition variation and microscopic structural changes affect key photovoltaic relevant properties in this family of materials.