Recently, the microstructure and photophysics research team led by Zhang Long and Dong Hongxing, researchers at the Laboratory of Laser and Infrared Materials of the Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, cooperated with domestic research institutions such as Nanjing Xiaozhuang University, Institute of Technical Physics, Chinese Academy of Sciences New progress has been made in nano-single-mode laser research. The team innovatively proposed and prepared a new all-inorganic perovskite RbPbBr3 material. The phase transition process of the perovskite material and its internal chemical mechanism were analyzed through theoretical simulations and experiments. Based on the perovskite RbPbBr3 material, a high degree of success was achieved. Quality, blue light single-mode laser output. Related papers have been published in German Applied Chemistry [Angewandte Chemie International Edition, 58, 201910617 (2019)].
Perovskite materials have attracted much attention in recent years because of their excellent properties in the visible spectrum, such as high absorption, high fluorescence emission, and broad-spectrum tuning. Recent studies have shown that perovskite materials have superior optical gain characteristics than previous optical materials, which makes them have great research value and application prospects in the field of micro-nano lasers. The status of inorganic perovskite materials is particularly important in perovskite materials. Its good chemical stability and large exciton binding energy are more conducive to the output of high-quality micro / nano lasers. However, limited by the tolerance factor constant t> 0.8, only the perovskite phase CsPbX3 has been successfully applied to the research of micro-nano lasers. Rb, as the same main group element of Cs, is expected to replace Cs to synthesize the full inorganic perovskite phase RbPbX3 material.
In addition, due to its soft lattice structure, perovskite materials are susceptible to phase transitions, and the study of phase transitions is important to understand the source of the excellent properties of perovskite materials. However, there are still many deficiencies in the analysis of the phase transition process and mechanism of the perovskite materials in current research, especially in the perovskite-non-perovskite phase transition, the optical characteristics of the materials often change greatly, which needs to be further explored by researchers. The tolerance factor of RbPbBr3 is 0.78, which is very suitable for analyzing the perovskite-non-perovskite phase transition process and chemical mechanism, and the perovskite phase RbPbBr3 has good optical characteristics, which is conducive to achieving high-quality micro-nano laser output. However, the pure all-inorganic perovskite phase RbPbBr3 faces great challenges in synthesis.
In this study, the researchers first analyzed the crystal structure, XRD diffraction pattern, and band structure of the perovskite phase and the non-perovskite phase RbPbBr3 by theoretical simulation. The theoretical analysis shows that the perovskite phase and the non-perovskite phase RbPbBr3 show direct and indirect band gaps respectively, and the theoretical analysis of the perovskite phase formation conditions. Based on the improved vapor transmission condensation technology combined with the heat treatment process, the researchers successfully prepared a high-quality submicron-scale three-dimensional spherical RbPbBr3, and realized the non-perovskite-perovskite phase transition, and the perovskite phase RbPbBr3 optical Excellent performance.
The researchers systematically studied the experimental conditions and chemical mechanism of the RbPbBr3 perovskite-non-perovskite phase transition, analyzed the detailed process of the phase transition of the inorganic perovskite material, and clarified its internal chemical mechanism. It is a perovskite material. The study of phase stability and optical properties has laid a solid theoretical and experimental basis. Inorganic perovskite RbPbBr3 microspheres have a smooth surface, a regular structure, and a controllable size. They have good fluorescence absorption and emission properties at 460nm and can be used in both gain media and optical microcavities to achieve micro-nano laser output. The researchers achieved high-quality, narrow-bandwidth blue light single-mode laser output in a high-quality RbPbBr3 microsphere cavity.
This research theory combined with experiments has clarified the detailed process of perovskite material phase transition and its internal chemical mechanism. The new all-inorganic perovskite RbPbBr3 is applied to high-quality single-mode laser output to further analyze the crystal structure of perovskite materials. The research on the relationship with the photoelectric performance and phase stability provides a solid theoretical and experimental basis, which is of great significance for the research of high-quality micro-nano laser devices, multi-color lasers and laser displays.