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.

中文翻译：

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钙钛矿型氯化钙forp型透明导体：关键的理论重估

最近，以氯化铅钙钛矿为代表 $铅{氯}_3$ 从理论上讲是理想的 $p$型透明导体因此引起了很多关注。但是，从实验上讲，长期以来，这些材料都是绝缘体，几乎不能转化为$p$非本征型导体。在这项工作中，我们系统地重新评估了$p$密度泛函理论计算的氯化钙钙钛矿型掺杂。我们发现先前预测的掺杂性是由于所使用的功能引起的高估，该功能给出了不合理的高价价带最大值。具有最佳混合参数并包含自旋-轨道耦合的混合功能可对带边缘位置进行适当描述，从而更好地评估掺杂性。我们的缺陷计算表明，氯化钙钙钛矿本质上是绝缘的，几乎不能转化为$p$由于缺乏有效的掺杂剂，所以与实验观察结果一致。我们的结果强调了适当描述带边缘位置对预测半导体的缺陷性质和掺杂性的重要性。