Liu Xingyi, Xu Xi, Li Ben, Yang Lanlan, Li Qi, Jiang Hong, Xu Dongsheng
Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
Small. 2020 Aug;16(31):e2002547. doi: 10.1002/smll.202002547. Epub 2020 Jun 30.
Double halide perovskites are a class of promising semiconductors applied in photocatalysis, photovoltaic devices, and emitters to replace lead halide perovskites, owing to their nontoxicity and chemical stability. However, most double perovskites always exhibit low photoluminescence quantum efficiency (PLQE) due to the indirect bandgap structure or parity-forbidden transition problem, limiting their further applications. Herein, the self-trapped excitons emission of Cs NaInCl by Sb-doping, showing a blue emission with high PLQE of 84%, is improved. Further, Sb/Mn codoped Cs NaInCl nanocrystals are successfully synthesized by the hot-injection method, showing a tunable dual-emission covering the white-light spectrum. The studies of PL properties and dynamics reveal that an energy transfer process can occur between the self-trapped excitons and dopants (Mn ). The work provides a new perspective to design novel lead-free double perovskites for realizing a unique white-light emission.
双卤化物钙钛矿是一类很有前景的半导体，由于其无毒和化学稳定性，可应用于光催化、光伏器件和发光体，以取代卤化铅钙钛矿。然而，由于间接带隙结构或宇称禁戒跃迁问题，大多数双钙钛矿的光致发光量子效率（PLQE）总是很低，这限制了它们的进一步应用。在此，通过锑掺杂改善了CsNaInCl的自陷激子发射，呈现出PLQE高达84%的蓝色发射。此外，通过热注入法成功合成了Sb/Mn共掺杂的CsNaInCl纳米晶体，呈现出覆盖白光光谱的可调谐双发射。对PL性质和动力学的研究表明，自陷激子和掺杂剂（Mn）之间可以发生能量转移过程。这项工作为设计新型无铅双钙钛矿以实现独特的白光发射提供了新的视角。
