The temperature-dependent time-resolved spectroscopies are employed to investigate the hot carrier characteristics in MAPbBr₃ nanocrystals (NCs). Simultaneously, the absorption and photoluminescence data exhibits that MAPbBr₃ NCs pass through cubic phase and tetragonal phase in turn as the temperature drops. As the phase transition from the cubic phase to the tetragonal phase, the band gap narrows, the shallow defects population that participates in the carrier dynamics and the Longitudinal-optical phonon energy (E_LO) decreases. We uncovered that the hot carrier can be induced in the MAPbBr₃ NCs through changing the photon flux and the temperature. Moreover, the hot carrier cooling time and the carrier heating effect in tetragonal phase improved in comparison with those in cubic phase, owing to the influence of bandgap, shallow defect and E_LO as mentioned above. These results can help us to further understand the hot carrier characteristics in the perovskite MAPbBr₃ NCs for designing and optimizing the perovskite-based optoelectronic devices of high performance.

温度相关的时间分辨光谱用于研究 MAPbBr ₃纳米晶体 (NC) 中的热载流子特性。同时，吸收和光致发光数据表明，随着温度的下降，MAPbBr ₃ NCs 依次通过立方相和四方相。随着从立方相到四方相的相变，带隙变窄，参与载流子动力学和纵光声子能量 ( E _LO )的浅缺陷群减少。我们发现可以在 MAPbBr _{3 中}诱导热载流子NCs 通过改变光子通量和温度。此外，由于上述带隙、浅缺陷和E _LO的影响，与立方相相比，四方相的热载流子冷却时间和载流子加热效果有所改善。这些结果可以帮助我们进一步了解钙钛矿 MAPbBr ₃ NCs 中的热载流子特性，以设计和优化基于钙钛矿的高性能光电器件。