Förster Resonance Energy Transfer-Based Design of High-Brightness CdSe/ZnS-CsPb(BrI)3 Nanocrystals for High-Performance Micro-LED Color Conversion Pixels

Abstract

Poor performance of red-emitting all-inorganic CsPbX₃ (X = Cl, Br, I) perovskite nanocrystals, specifically their low excitation efficiency in the blue and Ultraviolet A spectral ranges, limits their application as color conversion layers for micro-LED displays. In this work, new nanocomposites featuring CdSe/ZnS-CsPb(BrI)₃ heterostructure nanocrystals (hs-NCs) are develpoed, where the built-in Förster resonance energy transfer mechanism enhances red emission by efficiently transferring excitation energy from CdSe/ZnS to CsPb(BrI)₃. Consequently, the photoluminescence excitation spectrum of hs-NCs shifts to peak in the Ultraviolet A range, achieving a nearly highest photoluminescence quantum yield of 98.7% under 400 nm excitation. The hs-NCs demonstrate high compatibility with ultra-fine electrohydrodynamic inkjet printing, enabling fabrication of high-resolution, bright, and stable pure-red CCL arrays with a minimum pixel size of 8 µm. When combined with blue and green perovskite nanocrystals, these arrays achieve full-color pixel configurations with a color gamut of 131.3% NTSC standard. These results offer a substantial breakthrough on the quality of color conversion layers while opening new avenues for the advancement of micro-LED display technologies.