Effect of water on the effective Goldschmidt tolerance factor and photoelectric conversion efficiency of organic-inorganic perovskite: insights from first-principles calculations
Effect of water on the effective Goldschmidt tolerance factor and photoelectric conversion efficiency of organic-inorganic perovskite: insights from first-principles calculations
复制标题
水对有机-无机钙钛矿有效戈德施密特耐受因子和光电转换效率的影响：第一性原理计算的见解
DOI：
10.1039/c7cp02659e
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发表时间：
2017
影响因子：
3.3
通讯作者：
Liu Li-Min
中科院分区：
文献类型：
--
作者：
Tang Zhen-Kun;Zhu Ya-Nan;Xu Zhi-Feng;Liu Li-Min
水通常被认为是钙钛矿太阳能电池效率的主要杀手。然而，最近的实验结果表明，钙钛矿太阳能电池在适当潮湿的环境中具有更高的光电转换效率。在这项研究中，间隙水分子和钙钛矿吸收层的理论最大效率之间的关系进行了讨论，基于密度泛函理论计算。我们的计算结果表明，间隙水分子可以扩大有效的Goldschloss公差因子，这是一个经验的结构参数的钙钛矿材料的结构。原始MAPbI 3结构不是具有最高光电转换效率的理想钙钛矿结构。令人惊讶的是，适当的间隙水分子在增加光电转换效率方面对钙钛矿吸收剂是有益的。这可以归因于具有间隙水分子的钙钛矿结构的有效Goldschmidt耐受因子相对较大，从而影响钙钛矿结构的光电转换效率。计算结果表明，H_2O：MAPbI_3比为1/4-1/2的钙钛矿型吸收剂具有较高的光电转换效率。 该研究有助于深入理解间隙分子在钙钛矿结构中的作用，对高效钙钛矿电池中钙钛矿吸收剂的设计和优化具有重要意义。
Water is often believed to be the leading killer of perovskite solar cells’ efficiency. However, recent experimental results show that perovskite solar cells have higher photoelectric conversion efficiency in a suitably moist environment. In this study, the relationship between the interstitial water molecule and the theoretical maximum efficiency of the perovskite absorber layer is discussed based on density functional theory calculations. Our calculated results show that an interstitial water molecule can enlarge the effective Goldschmidt tolerance factor, which is an empirical structural parameter for the structure of the perovskite material. The primitive MAPbI3 structure is not the ideal perovskite structure with the highest photoelectric conversion efficiency. Surprisingly, appropriate interstitial water molecules are beneficial to perovskite absorbers in terms of increasing photoelectric conversion efficiency. This can be attributed to the relatively larger effective Goldschmidt tolerance factor of the perovskite structure with an interstitial water molecule, which affects the photoelectric conversion efficiency of the perovskite structure. Our calculations indicate that the perovskite absorbers with a H2O : MAPbI3 ratio of 1/4–1/2 have a relatively higher photoelectric conversion efficiency. This study helps us understand the role of the interstitial molecule in the perovskite structure deeply, which is very useful in the design and optimization of the perovskite absorbers for high-efficiency perovskite cells.