Dual Self-Trapped Exciton Emission with Ultrahigh Photoluminescence Quantum Yield in CsCu2I3 and Cs3Cu2I5 Perovskite Single Crystals

作者：Lin, Richeng; Zhu, Qun; Guo, Quanlin; Zhu, Yanming; Zheng, Wei^*; Huang, Feng^*

来源：Journal of Physical Chemistry C, 2020, 124(37): 20469-20476.

DOI：10.1021/acs.jpcc.0c07435

• RADIATIVE RECOMBINATION
• BALANCED PHOTODETECTION
• LUMINESCENCE
• ABSORPTION
• BLUE
• LIFETIME

Low-dimensional metal halide perovskites possessing a large exciton binding energy have shown great promise in achieving efficient photonic emission required in the fields of lighting sources and display. Here, efficient dual self-trapped exciton (STE) emissions are directly observed in a low-dimensional inorganic copper iodine quasi-perovskite single crystal. The dual STEs have natural structure-oriented performance, showing a strong electron-phonon coupling. Temperature-dependent PL spectra and Raman spectra demonstrate a thermal-assisted radiative recombination of dark STEs, and based on such a mechanism, an ultrahigh photoluminescence quantum yield (PLQY similar to 100%) was obtained in bulk crystals with a zero-dimensional electronic structure, favoring photoexcited STEs to gain a large binding energy of up to 563 meV. All these results above show a great advancement in high-efficiency photonic emission through the low-dimensional electronic structure and STE radiative recombination.

• 单位
  光电材料与技术国家重点实验室; 中山大学