Abstract Owing to the superior performance of lead-halide perovskites in various optoelectronic devices, their low-dimensional counterparts of quantum-confined nanocrystals (NCs) have started drawing intensive research attention. Here we report a systematic study on the optical properties of single FAPbBr3 NCs, which demonstrate high-purity single-photon emission, large absorption cross-section and narrow photoluminescence linewidth. Interestingly, linearly-polarized emission can be partially observed in single FAPbBr3 NCs at the room temperature, the degree of which is significantly enhanced at the cryogenic temperature. The above polarization phenomenon is attributed to the large energy-level splitting of the bright-exciton states, leading to efficient exciton recombination from the lowest state with a 1D dipole moment. This unique feature of linear polarization in the optical emission of single FAPbBr3 NCs has not only provided a deep understanding of their exciton energy-level structures, but also suggested potential polarization-oriented applications such as in photo-detectors, light-emitting diodes and lasers.

中文翻译：

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单个钙钛矿 FAPbBr3 纳米晶体的偏振发射

摘要 由于卤化铅钙钛矿在各种光电器件中的优越性能，它们的低维量子限域纳米晶体 (NCs) 已开始引起广泛的研究关注。在这里，我们报告了对单个 FAPbBr3 NC 的光学性质的系统研究，该研究证明了高纯度的单光子发射、大的吸收截面和窄的光致发光线宽。有趣的是，在室温下可以在单个 FAPbBr3 NCs 中部分观察到线性极化发射，其程度在低温下显着增强。上述极化现象归因于亮激子态的大能级分裂，导致具有一维偶极矩的最低态的激子有效复合。