Dual Wettability Control of Coffee Ring Effect in QDCC Layer with BM

Quantum dot color conversion (QDCC) layer is a key structure to enhance the color gamut and brightness of display devices. But its high precision preparation still faces challenges. This study compared the performance of piezoelectric inkjet (PIJ) and electrohydrodynamic (EHD) printing in QDCC layer preparation and finds that EHD significantly improves film uniformity by virtue of finer droplet control. This study focused on the influence of the black matrix (BM) surface on the ink behavior, confirming that the hydrophobic BM treated with N2O can effectively suppress the coffee ring effect. By optimizing the synergy between the BM treatment and the EHD process, the QDCC layer with high uniformity was successfully prepared, providing a practical solution for quantum dots (QDs) integration in micro display devices.