Metal halide perovskites (MHPs) have been developed rapidly in light-emitting diodes (LEDs), laser, solar cells, photodetectors and other fields in recent years due to their excellent photoelectronic properties, which attract more researchers’ attention. Perovskite LEDs show great promise in the next generation of lighting and display technologies, and external quantum efficiency (EQE) values of polycrystalline thin-film perovskite LEDs (PeLEDs) exceed 20%, which are undoubtedly identified as a big breakthrough in lighting and display fields. However, toxicity and instabilities of lead-based MHPs remain major obstacles limiting their further commercial applications. The exploration and development of lead-free MHPs (LFMHPs) are regarded as most facile strategies to solve these problems. Compared with lead-based perovskites, LFMHPs exhibit better stabilities and broadband emission. With continuous development of LFMHPs, their photoluminescence quantum yields (PLQYs) are up to 99%, facilitating them as ideal emitters. In this review, structures and features of LFMHPs are analyzed firstly, and preparation methods of LFMHP with various structures and configuration are discussed. Then, mechanisms and strategies for improving emission performance of white LEDs based on LFMHPs are demonstrated. Finally, their challenges in commercial production and perspectives are prospected.

中文翻译：

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用于发光的无铅金属卤化物钙钛矿的机遇和挑战


近年来，金属卤化物钙钛矿 （MHP） 因其优异的光电性能在发光二极管 （LED）、激光器、太阳能电池、光电探测器等领域得到了快速发展，引起了更多研究人员的关注。钙钛矿 LED 在下一代照明和显示技术中显示出巨大的前景，多晶薄膜钙钛矿 LED （PeLED） 的外部量子效率 （EQE） 值超过 20%，这无疑被认为是照明和显示领域的重大突破。然而，基于铅的 MHP 的毒性和不稳定性仍然是限制其进一步商业应用的主要障碍。探索和开发无铅 MHP （LFMHP） 被认为是解决这些问题的最简单策略。与铅基钙钛矿相比，LFMHP 表现出更好的稳定性和宽带发射。随着 LFMAHP 的不断发展，它们的光致发光量子产率 （PLQY） 高达 99%，使其成为理想的发射器。本文首先分析了 LFMHPs 的结构和特征，并讨论了具有各种结构和构型的 LFMHP 的制备方法。然后，展示了基于 LFMHP 提高白光 LED 发射性能的机制和策略。最后，展望了他们在商业生产和前景方面的挑战。