Synergistic Ligand Engineering and Electrohydrodynamic Printing for High-Resolution and Efficient Perovskite Nanocrystal Color-Conversion Micropixels

Perovskite nanocrystals (PeNCs) are regarded as promising color-conversion materials for high-resolution Micro-LED displays; however, their implementation is severely hindered by two critical challenges: insufficient patterning precision and apparently reduced efficiency of color conversion layers (CCLs). Herein, we propose a synergistic strategy that integrates ligand engineering with electrohydrodynamic (EHD) printing to simultaneously address these bottlenecks. By introducing dodecylbenzenesulfonic acid (DBSA) as a surface ligand for CsPbBr3 PeNCs, a highly compatible ink for EHD printing is achieved, enabling the fabrication of highly uniform PeNC micropixel arrays with well-defined morphology and precisely controlled dimensions. Meanwhile, DBSA ligands efficiently passivate surface defects, significantly reducing nonradiative recombination in the solid-state CCLs and suppressing the ion migration under the high electric filed, therefore boosting the photoluminescence quantum yield to over 65%. By integrating red and green DBSA-modified PeNC micropixel arrays with blue Micro-LED chips, a wide color gamut covering 136.5% of the NTSC standard can be achieved. This work provides a viable cooperative solution for concurrently overcoming morphological control and efficiency degradation in PeNC CCLs, offering valuable insights toward the development of high-performance and high-resolution color conversion Micro-LED displays.