Polarization improvement of CsPbClBr2 quantum dot film by laser direct writing technology

Inorganic halogen perovskite quantum dots not only have high fluorescence quantum efficiency, but also can emit polarized light in solution or thin film. These excellent performances make perovskite quantum dots promising to be used in next-generation displays. In this study, we develop laser direct writing technology to improve the emitted light polarization of CsPbClBr2 quantum dot film. Without using an additional polarizer, we prove that the polarization degree is maximumly increased by about 56%, and the reasons are analyzed from three perspectives: laser scanning space, laser power, and film thickness. In addition, the lifetime of the fluorescence is also greatly improved after laser treatment. The results we obtain provide the possibility for production of a new generation of displays.