Lanthanides have been widely explored as optically active dopants in inorganic crystal lattices, which are often insulating in nature. Doping trivalent lanthanide (Ln³⁺) into traditional semiconductor nanocrystals, such as CdSe, is challenging because of their tetrahedral coordination. Interestingly, CsPbX₃ (X = Cl, Br, I) perovskite nanocrystals provide the octahedral coordination suitable for Ln³⁺ doping. Over the last two years, tremendous success has been achieved in doping Ln³⁺ into CsPbX₃ nanocrystals, combining the excellent optoelectronic properties of the host with the f-f electronic transitions of the dopants. For example, the efficient quantum cutting phenomenon in Yb³⁺-doped CsPb(Cl,Br)₃ nanocrystals yields a photoluminescence quantum yield close to 200%. Other approaches of Ln³⁺ doping and codoping have enabled promising proof-of-principle demonstration of solid-state lighting and solar photovoltaics. In this perspective article, we highlight the salient features of the material design (including doping in Pb-free perovskites), optical properties and potential optoelectronic applications of lanthanide-doped metal halide perovskite nanocrystals. While review articles on doping different metal ions into perovskite nanocrystals are present, the present review-type article is solely dedicated to lanthanide-doped metal halide perovskite nanocrystals.

镧系元素已被广泛地用作无机晶格中的光学活性掺杂剂，而无机晶格通常是自然绝缘的。由于三价镧系元素（Ln ³⁺）的四面体配位，因此将其掺杂到传统的半导体纳米晶体（如CdSe）中具有挑战性。有趣的是，钙钛矿型CsPbX ₃（X = Cl，Br，I）纳米晶体提供了适合Ln ³⁺掺杂的八面体配位。在过去的两年中，在将Ln ³⁺掺杂到CsPbX ₃纳米晶体中方面取得了巨大的成功，将基质的优异光电性能与掺杂剂的ff电子跃迁相结合。例如，Yb ^3+中的有效量子切割现象掺杂的CsPb（Cl，Br）₃纳米晶体产生的光致发光量子产率接近200％。Ln ³⁺掺杂和共掺杂的其他方法已使固态照明和太阳能光伏技术的原理验证示范成为可能。在这篇观点文章中，我们重点介绍了镧掺杂金属卤化物钙钛矿纳米晶体的材料设计（包括在无铅钙钛矿中掺杂）的显着特征，光学特性和潜在的光电应用。尽管存在关于将不同的金属离子掺杂到钙钛矿纳米晶体中的评论文章，但是本评论类型的文章仅致力于掺杂镧系元素的金属卤化物钙钛矿纳米晶体。