Research on the importance of substrate morphological features in high-power mode for the perovskite film’s photoluminescence stability

Abstract

In this work, we investigate the photoluminescence stability of CsPbBr₃ perovskite quantum dot films under high-power excitation, focusing on the critical role of substrate morphology in modulating thermal dissipation and absorptance evolution. Conventional two-dimensional substrates induce severe thermal accumulation and spectral instability during continuous wave excitation, which compromises photoluminescence efficiency and color mixing accuracy in white-light communication. To overcome these challenges, we propose a novel three-dimensional microporous waveguide substrate combined with a method of ice-templated and spray-assisted deposition to fabricate stratified CsPbBr₃/CsPbI₂Br quantum dot films. This three-dimensional configuration enhances thermal dissipation, mitigates thermally induced degradation of perovskite quantum dots and stabilizes photoluminescence under optically modulated excitation. Experimental results show that the films based on the three-dimensional substrate exhibit a photostability threshold approximately 2.5 times higher than those based on planar substrates, demonstrating a significant enhancement in photoluminescence stability. Furthermore, the photoluminescence emission intensity is increased by approximately 4.35 times compared to the two-dimensional substrate. Notably, white-light mixing based on this structure is effectively localized in the CIE 1931 color space, with color mixing fluctuation reduced by approximately 81.68 % compared to the two-dimensional substrate. Our results demonstrate that the three-dimensional substrate, as a key determinant of photoluminescence performance, offers a promising path for the development of power-type perovskite devices.