Quantum dot (QD) color conversion layers (CCLs) present an economical and reliable approach to achieve full-color micro-LED displays. Microfluidic technology demonstrates significant advantages for patterning and integrating multicolor QDs, including high precision, rapid processing, low material consumption, and low fabrication costs. However, preparing high-resolution CCLs with low optical crosstalk remains challenging due to limitations in microfluidic chip design induced by swelling of polydimethylsiloxane (PDMS) microchannels in nonpolar solvents utilized for QD dispersion. In this study, we developed a QD solution with a polymer additive that effectively suppresses PDMS swelling, making injection of QD solution into small-sized PDMS microchannels on chromium-patterned microhole glass substrates possible. The resulting QD CCLs exhibit high luminescence uniformity and a high resolution of 1285 ppi, with a subpixel dimension of 5 μm × 5 μm, which is the smallest dimension reported for CCLs fabricated by microfluidic technology. Furthermore, our innovative integration of chromium-patterned microhole glass substrates within a microfluidic device provides unprecedented optical isolation, effectively eliminating intersubpixel crosstalk in CCLs. By integrating optimized red and green QD CCLs with a blue GaN micro-LED array, we successfully fabricated a full-color micro-LED prototype with a resolution of 600 ppi and a wide color gamut of 115% NTSC. Owing to their high resolution, uniform luminescence, and low optical crosstalk, the proposed microfluidic technology holds significant promise for advancing next-generation full-color micro-LED displays.
To address issues such as uneven particle size, agglomeration, low luminescence efficiency, and poor stability in the nanosizing of Mn4+-doped fluoride red phosphors, this study combines solid solution engineering and aliovalent charge compensation to prepare high-performance K2LiB1–xB′xF6:Mn4+ (B, B′ = Al, Ga, In) nanoparticles (FNPs). Using an HF-free coprecipitation method for the synthesis of solid-solution matrices, followed by a ligand-assisted reprecipitation step that employs a small amount of HF to dissolve K2MnF6 to rapidly and uniformly incorporate Mn4+ into the matrices, and the particle size is reduced from 33.32 to 16.05 nm with improved dispersibility by adjusting the volume ratio of oleic acid (OA) to oleylamine (OAm) ligands; through the gradual solid solution of Al3+, Ga3+, and In3+, the regulatory mechanism of lattice distortion and local crystal field on luminescence is revealed, with optimal luminescence intensity achieved at specific solid-solution ratios and the emission peak blue-shifted from 636 to 632 nm. Zn2+ codoping for charge compensation enhances the luminescence intensity of the 0.9% Mn4+-doped sample by 120%, with the internal quantum efficiency (IQE) increased to 40.01%, and the fluorescence lifetime extended to 4.11 ms. The FNPs have good thermal stability (56% retention at 150 °C) and moisture resistance (85% retention after 240 h in water). Packaged white light-emitting diode (WLED) exhibits a luminous efficacy of 20.54 lm W–1, and the fluorescent ink enables red–green anticounterfeiting display under UV excitation, providing insights into applications in high-end display and lighting fields, especially micro-LED color conversion layers, WLED packaging, and anticounterfeiting/encryption inks.
危险品化学品经营许可证（带存储）