Superfluorescence and nonlinear optical response of CH 3 NH 3 PbBr 3 -based mesostructures: applications to amplified spontaneous emission and ultrafast lasers

作者：Qianwen Wang, Jingjing Yang, Z. Zhan, Huiling Kou, Zhengzheng Liu, Yubo Wang, Xueyao Liu, Siyu Dong, Tuo Li, Xiaofeng Zou, Wenbin Zhou, Qiuting Yan, Juan Du, Dengwang Li, Chen Cheng, Shuhao Si · 发表于：Optics Express · 年份：2024 · DOI：10.1364/oe.543117 · 被引用次数：7 · 研究领域：Perovskite Materials and Applications、Solid State Laser Technologies、Advanced Fiber Laser Technologies

Metal halide perovskites have unique luminescent properties that make them an attractive alternative for high quality light-emitting devices. However, the poor stability of perovskites with many defects and the long cycle time for the preparation of perovskite nanocomposites have hindered their production and application. Here, we prepared the perovskite mesostructures by embedding MAPbBr 3 nanocrystals in the mesopores on the surface of silica nanospheres and mixing the nanospheres with silver nanowires and poly(methyl methacrylate) (PMMA), and further explored their optical properties. The perovskite mesostructures exhibited superfluorescence (SF) under 785 nm laser excitation and the decay time was as short as 0.59 ps using a double exponential decay fit. The optical nonlinearity of these perovskite mesostructures under two-photon excitation was investigated by the Z-scanning technique. The samples exhibited both two-photon absorption (TPA) and saturation absorption (SA) with nonlinear absorption coefficients β ranging approximately 0.15 to 0.89 cm/GW corresponding to the TPA, and a saturation intensity of about 0.026 GW/cm 2 was determined. In addition, the quality of the perovskite mesostructures was shown to be significantly improved, including an increase in radiative efficiency and an extension of the optical gain lifetime. The samples were excited by a two-photon femtosecond laser pump at room temperature and atmospheric pressure, and the laser peak appeared at 540.1...