Wang Zhongyi, Zhang Ruiling, Mao Xin, Zheng Daoyuan, Liu Siping, Liu Feng, Han Keli, Yang Bin
Institute of Molecular Sciences and Engineering, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao, 266237 P.R. China.
State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, 116023 P.R. China.
J Phys Chem Lett. 2022 Sep 15;13(36):8613-8619. doi: 10.1021/acs.jpclett.2c02351. Epub 2022 Sep 8.
Halide double perovskites have aroused substantial research interest because of their unique optical properties and intriguing flexibility for various compositional adjustments. Herein, we report the synthesis and photophysics of rare-earth element yttrium (Y)-based double perovskite single crystals (SCs) and nanocrystals (NCs). The pristine CsNaYCl bulk SCs exhibit a weak sky-blue emission with a low photoluminescence quantum yield (PLQY) of 7.68% based on the self-trapped exciton (STE), while no PL emission was observed for NCs. Excitingly, the STE emission of SCs and NCs is greatly enhanced via Sb doping. The optimized CsNaYCl:Sb SCs and NCs exhibit high PLQYs up to 82.5% and 51.8%, respectively. Theoretical calculations and charge-carrier dynamic studies demonstrate that the giant emission enhancement after Sb doping is related with the enhancement of the sensitization of the emissive STE states, the passivating of the nonradiative carrier trapping processes, and the regulation of carrier-phonon coupling.
卤化物双钙钛矿因其独特的光学性质和在各种成分调整方面的有趣灵活性而引起了大量研究兴趣。在此，我们报告了基于稀土元素钇（Y）的双钙钛矿单晶（SCs）和纳米晶体（NCs）的合成及光物理性质。原始的CsNaYCl块状SCs基于自陷激子（STE）表现出微弱的天蓝色发射，光致发光量子产率（PLQY）较低，为7.68%，而NCs未观察到PL发射。令人兴奋的是，通过Sb掺杂，SCs和NCs的STE发射得到了极大增强。优化后的CsNaYCl:Sb SCs和NCs的PLQY分别高达82.5%和51.8%。理论计算和电荷载流子动力学研究表明，Sb掺杂后发射的巨大增强与发射性STE态的敏化增强、非辐射载流子俘获过程的钝化以及载流子 - 声子耦合的调节有关。
