Ge Chao, Li Yachao, Song Haiying, Xie Qiyuan, Zhang Leilei, Ma Xiaoran, Liu Junfeng, Guo Xiangjing, Yan Yinzhou, Liu Danmin, Zhang Wenkai, Liu Shibing, Liu Yang
Institute of Laser Engineering, School of Physics and Optoelectronic Engineering, Beijing University of Technology, 100124, Beijing, China.
State Key Laboratory of Crystal Materials, Shandong University, 250100, Jinan, China.
Nat Commun. 2024 Jan 30;15(1):914. doi: 10.1038/s41467-024-45055-y.
Perovskite materials and their applications in optoelectronics have attracted intensive attentions in recent years. However, in-depth understanding about their anisotropic behavior in ultrafast carrier dynamics is still lacking. Here we explore the ultrafast dynamical evolution of photo-excited carriers and photoluminescence based on differently-oriented MAPbBr wafers. The distinct in-plane polarization of carrier relaxation dynamics of the (100), (110) and (111) wafers and their out-of-plane anisotropy in a picosecond time scale were found by femtosecond time- and polarization-resolved transient transmission measurements, indicating the relaxation process dominated by optical/acoustic phonon interaction is related to photoinduced transient structure rearrangements. Femtosecond laser two-photon fabricated patterns exhibit three orders of magnitude enhancement of emission due to the formation of tentacle-like microstructures. Such a ultrafast dynamic study carried on differently-oriented crystal wafers is believed to provide a deep insight about the photophysical process of perovskites and to be helpful for developing polarization-sensitive and ultrafast-response optoelectronic devices.
近年来,钙钛矿材料及其在光电子学中的应用引起了广泛关注。然而,目前仍缺乏对其在超快载流子动力学中各向异性行为的深入理解。在此,我们基于不同取向的MAPbBr晶片,探索了光激发载流子和光致发光的超快动力学演化。通过飞秒时间分辨和偏振分辨瞬态透射测量,发现(100)、(110)和(111)晶片的载流子弛豫动力学在面内具有明显的偏振特性,且在皮秒时间尺度上具有面外各向异性,这表明由光学/声学声子相互作用主导的弛豫过程与光致瞬态结构重排有关。飞秒激光双光子制备的图案由于形成了触手状微结构,其发射增强了三个数量级。对不同取向的晶体晶片进行的这种超快动力学研究,有望为钙钛矿的光物理过程提供深入见解,并有助于开发偏振敏感和超快响应的光电器件。