Tin‐halide perovskites (THP) are emerging materials for photovoltaics with optoelectronic properties potentially rivaling lead‐based analoges. Their efficiencies in solar cells are, however, severely limited by the high sensitivity of tin to oxygen and the heavy p‐doping natively present in the material. While the effects of oxygen can be mitigated by using reducing agents upon the synthesis and by encapsulating the device, the native p‐doping caused by the high density of acceptor defects remains a challenge to be further addressed for prolonging carrier lifetimes and, consequently, device efficiency. In this work, potential compositional engineering strategies aimed at reducing the p‐doping of this class of materials and increasing their efficiency in solar cells are investigated. Based on density functional theory simulations it is demonstrated that THP doping with d1s2 trivalent ions effectively decreases the hole background density and the density of the deep defects responsible for the non‐radiative recombination in these materials. This effect is enhanced by alloying iodide with small fractions of bromide, up to 33%. Higher bromide fractions, instead, are detrimental due to the increased non‐radiative recombination. These results may provide useful guidelines to experimentalists for improving the optoelectronic quality of THPs and consequently of the ensuing devices.

中文翻译：

---

三价离子掺杂与卤化物合金化相结合提高锡钙钛矿的效率


卤化锡钙钛矿（THP）是新兴的光伏材料，其光电特性可能与铅基类似物相媲美。然而，它们在太阳能电池中的效率受到锡对氧的高敏感性以及材料中本身存在的重p掺杂的严重限制。虽然可以通过在合成时使用还原剂和封装器件来减轻氧的影响，但由高密度受主缺陷引起的本征 p 掺杂仍然是一个需要进一步解决的挑战，以延长载流子寿命，从而延长器件寿命。效率。在这项工作中，研究了旨在减少此类材料的 p 掺杂并提高其在太阳能电池中的效率的潜在成分工程策略。基于密度泛函理论模拟，证明 THP 掺杂 d1s2 三价离子有效降低了空穴背景密度和导致这些材料中非辐射复合的深层缺陷密度。通过将碘化物与少量的溴化物（最高可达 33%）进行合金化，可以增强这种效果。相反，较高的溴化物分数是有害的，因为非辐射复合增加。这些结果可以为实验者提供有用的指导，以提高 THP 的光电质量，从而提高后续设备的光电质量。