Lead chloride perovskites for p -type transparent conductors: A critical theoretical reevaluation
Lead chloride perovskites for p -type transparent conductors: A critical theoretical reevaluation
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DOI：
10.1103/physrevmaterials.4.115201
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发表时间：
2020-11
影响因子：
3.4
通讯作者：
Sanlue Hu;Bing Xia;Yanfa Yan;Zewen Xiao
中科院分区：
文献类型：
--
作者：
Sanlue Hu;Bing Xia;Yanfa Yan;Zewen Xiao
最近，以{CSPB}{CSPB}为代表的氯化铅钙钛矿型透明导体在理论上被预测为理想的P型透明导体，因而引起了人们的极大关注。然而，在实验上，这些材料长期以来一直被认为是绝缘体，很难通过非本征掺杂转换为$p$型导体。在这项工作中，我们用密度泛函理论计算系统地重新评估了氯化铅钙钛矿的$p‘型掺杂性。我们发现，先前预测的掺杂率是由于所采用的泛函导致的高估，从而给出了不合理的高位价带最大值。经过优化的混合参数和自旋-轨道耦合的混合泛函给出了合适的能带边缘位置的描述，从而更好地评估了掺杂性。我们的缺陷计算表明，氯化铅钙钛矿具有本征绝缘性，由于缺乏有效的掺杂剂，很难转变为$p‘型导体，这与实验观察到的结果一致。我们的结果强调了对能带边缘位置的适当描述对于预测半导体的缺陷性质和掺杂性的重要性。
Recently, lead chloride perovskites represented by $\mathrm{CsPb}{\mathrm{Cl}}_{3}$ have been theoretically predicted to be ideal $p$-type transparent conductors and hence have attracted a lot of attention. However, experimentally, these materials have long been known to be insulators that can hardly be converted to $p$-type conductors by extrinsic doping. In this work, we systematically reevaluate the $p$-type dopability of lead chloride perovskites by density functional theory calculations. We find that the previously predicted dopability is due to an overestimation caused by the functional employed that gives an unreasonable high-lying valence band maximum. The hybrid functional with an optimized mixing parameter and the inclusion of spin-orbit coupling gives a suitable description of the band edge positions and thus a better assessment of the dopability. Our defect calculations suggest that lead chloride perovskites are intrinsically insulating and can hardly be converted to $p$-type conductors due to the lack of effective dopants, in agreement with the experimental observations. Our results highlight the importance of the suitable description of band edge positions on the prediction of defect properties and dopability of semiconductors.