Continuous-flow synthesis of CsPbI3/TiO2 nanocomposites with enhanced water and thermal stability

Abstract

The inherent poor stability of CsPbI₃ nanocrystals hinders the practical application of this material. Therefore, it is still a challenge to improve the stability of CsPbI₃ nanocrystals and realize their large-scale continuous preparation. In this work, we report the preparation of CsPbI₃/TiO₂ nanocomposites with high stability by a microfluidic method. After the combination of CsPbI₃ nanorods with TiO₂, the PL intensity increased by 1.3 times under excitation at 577 nm due to the passivating effect of TiO₂ on the surface of CsPbI₃ nanorods and its carrier transport characteristics. Meanwhile, due to the coating of TiO₂, the surface exposure area of CsPbI₃ nanorods is reduced, which blocks external environmental effects to some extent and effectively improves the stability of CsPbI₃ nanorods. Finally, an LED with a color gamut of 142% NTSC and a color temperature (CCT) of 3952 K was obtained by combining CsPbI_1.5Br_1.5/TiO₂ and CsPbBr₃/TiO₂ nanocomposites with a blue light chip (455 nm). This study shows that the continuous and controllable synthesis of all inorganic halide perovskite nanocrystals by a microfluidic method is of great significance in the fabrication of high-performance optoelectronic materials and display devices.