The rise and commercialization of perovskite solar cells (PSCs) is hindered by the toxicity of lead present in the perovskites used as the solar light absorber. To counter this problem, lead (Pb) can be fully (lead‐free) or partially (lead‐less) replaced by diverse elements. The former compounds suffer from poor efficiency and poor stability, whereas the later appear more promising. Herein, a survey of the methods reported in the literature to reduce Pb content in PSCs to fabricate “lead‐less” (also called “lead‐deficient”) PSCs is offered. First, the comparison of Sn and Pb elements and the partial replacement of Pb by Sn are developed. Then, its substitution by either Ge, Sr, or other alkaline‐earth‐metals, transition metals, and elements from columns 12, 13, and 15 of the periodic table are detailed. The new families of perovskites based on the insertion of organic cations to replace lead and halogen units, namely the “lead‐deficient” and “hollow” halide perovskites are then presented and discussed. Finally, atypical ways to reduce the toxicity of PSCs are presented: perovskite layer thickness reduction via optimization of photon collection, integration of photonic structures, and usage of recycled lead. The current achievements and the outlook of those strategies are presented and discussed.

中文翻译：

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铅少卤化物钙钛矿太阳能电池

钙钛矿太阳能电池（PSC）的兴起和商业化受到用作太阳光吸收剂的钙钛矿中存在的铅的毒性的阻碍。为了解决这个问题，铅（Pb）可以完全（无铅）或部分（无铅）替换为各种元素。前者的化合物效率低且稳定性差，而后者则更有希望。本文对文献报道的减少PSC中Pb含量以制造“无铅”（也称为“铅缺乏”）PSC的方法进行了调查。首先，开发了Sn和Pb元素的比较以及用Sn替代Pb的方法。然后，详细说明了其被Ge，Sr或其他碱土金属，过渡金属以及元素周期表第12、13和15列中的元素取代的情况。然后介绍并讨论了基于插入有机阳离子以取代铅和卤素单元的新型钙钛矿家族，即“铅缺乏”和“空心”卤化物钙钛矿。最后，提出了减少PSC毒性的非典型方法：通过优化光子收集，整合光子结构和使用再生铅来减少钙钛矿层的厚度。介绍并讨论了这些策略的当前成就和前景。和使用回收铅。介绍并讨论了这些策略的当前成就和前景。和使用回收铅。介绍并讨论了这些策略的当前成就和前景。