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

Poor performance of red‐emitting all‐inorganic CsPbX 3 (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.