Shanghai Opto-Machine has made important progress in the research of single-mode laser in micro-nano structure

[ Instrument Network Instrument Development ] Recently, the microstructure and photophysics research team led by Zhang Long Researcher and Dong Hongxing Researcher of Laser and Infrared Materials Laboratory of Shanghai Institute of Optics and Mechanics cooperated with domestic research institutes such as Nanjing Xiaozhuang College and Institute of Technology of Chinese Academy of Sciences. Significant progress has been made in the field of micro-nano single-mode laser research. The team innovatively proposed and prepared a new type of all-inorganic perovskite RbPbBr3 material, and analyzed the phase transition process and its internal chemical mechanism of perovskite material through theoretical simulation and experiment, and successfully achieved high quality based on perovskite RbPbBr3 material. Quality, blue light single mode laser output. Related papers are published in [Angewandte Chemie International Edition, 58, 201910617 (2019)].

Perovskite materials have attracted much attention in recent years due to their excellent characteristics such as high absorption, high fluorescence emission, and wide spectral tuning in the visible region. Recent studies have shown that perovskite materials have superior optical gain characteristics compared to previous optical materials, which makes them have great research value and application prospects in the field of micro-nano lasers. The position of inorganic perovskite materials in perovskite materials is particularly important, and its good chemical stability and large exciton binding energy are more conducive to the output of high-quality micro-nano lasers. However, subject to the limitation of the tolerance factor constant t>0.8, only the perovskite phase CsPbX3 has been successfully applied to the study of micro/nano lasers. As a Cs main group element, Rb is expected to replace Cs to synthesize all-inorganic perovskite phase RbPbX3 materials. In addition, due to its soft lattice structure, perovskite materials are prone to phase transformation, and phase transition studies are critical to understanding the source of the superior properties of perovskite materials. However, the current research has many shortcomings in the analysis of the phase transition process and mechanism of perovskite materials. Especially in the perovskite-non-perovskite phase transition, the optical properties of materials often change greatly, and the researchers need to further explore. RbPbBr3 has a tolerance factor of 0.78, which is very suitable for the analysis of the process and chemical mechanism of perovskite-non-perovskite phase transformation, and the perovskite phase RbPbBr3 has good optical properties, which is conducive to high-quality micro-nano laser output, but pure The all-inorganic perovskite phase RbPbBr3 faces great challenges in terms of synthesis.

Fully inorganic perovskite phase RbPbBr3 high quality single mode laser

In this study, the researchers first analyzed the crystal structure, XRD diffraction pattern and band structure of perovskite phase and non-perovskite phase RbPbBr3 by theoretical simulation. Theoretical analysis shows that the perovskite phase and the non-perovskite phase RbPbBr3 exhibit direct and indirect band gaps, respectively, and theoretically analyze the formation conditions of the perovskite phase. Based on the improved gas phase transfer condensation technology combined with the heat treatment process, the researchers successfully prepared high-quality submicron-scale three-dimensional spherical RbPbBr3, and realized non-perovskite-perovskite phase transition in the experiment, perovskite phase RbPbBr3 optics Excellent performance. The researchers systematically studied the experimental conditions and chemical mechanisms of the RbPbBr3 perovskite-non-perovskite phase transition, and analyzed the detailed process of the phase transition of the inorganic perovskite material and clarified its intrinsic chemical mechanism, which is a perovskite material. The study of phase stability and optical properties has laid a solid theoretical and experimental basis. The inorganic perovskite RbPbBr3 microspheres have smooth surface, regular structure and controllable size. They have good fluorescence absorption and emission properties at 460nm, and can be used for gain medium and optical microcavity to realize micro-nano laser output. The researchers achieved high-quality, narrow-bandwidth blue-light single-mode laser output in high-quality RbPbBr3 microspheres (Figure 1). The research theory combines experiments to clarify the detailed process of the phase transition of perovskite materials and its intrinsic chemical mechanism, and apply the new all-inorganic perovskite RbPbBr3 to high-quality single-mode laser output for further analysis of the crystal structure of perovskite materials. The relationship between photoelectric properties and phase stability provides a solid theoretical and experimental basis, and is of great significance for the research of high-quality micro-nano laser devices, multi-color lasers and laser displays.

Relevant work has been supported by the National Natural Science Foundation of China and the Shanghai Qixing Project.