EHD Spinning process for QD color converting display

This paper discusses the novel process for quantum-dot color converter (QDCC) patterning of a display module. Electrohydrodynamics (EHD) spinning of QD inks on a glass substrate provides a uniform color-converting layer showing near zero defects and remarkable material usage. This process can directly print pixels of several microns in width without costly photolithography. Continuous QD ink stream by EHD spinning has a smaller stream diameter than that of an ejecting nozzle. Thus, it enables high spatial resolution with uniform QDs film thickness. Utilizing high viscosity (∼1000 cPs) inks gives the advantage of high QD content without solvent that can improve color conversion efficiency and reliability. We identified the basic properties of QDs ink and substrate for EHD spinning and further proved patterning manufacturability with an optimized printing process. With this printing method, a broad range of display form factors from a modular panel for 4k and 8k TV to a high-resolution mobile display can be implemented.