47‐1: Invited Paper: Electrohydrodynamic Inkjet Specialized Perovskite non‐polar Ink for Printing Color Conversion Layer of Micro‐LED Display

In micro‐LED display, electrohydrodynamic (EHD) inkjet printing has been proven competent in patterning the fluorescent quantum dots in to color conversion arrays with the highest spatial resolution, compared with other inkjet printing technologies. In this article, we introduce basic thoughts of designing the EHD specialized inks, aiming to optimized the properties of ink for commercially readily products. First, from the view point of electrodynamics, the basic mechanism of electrical driving is introduced, in which the difference between two type of ink, the ionic polar ink and the colloidal nonpolar ink are compared. Secondly, the interconnections and the physical problem between ink engineering and the optimization targets: ejection control, pixel homogeneity, stability and efficiency are revealed. The correlation between dielectric constant and viscosity are described in theory. It is pointed out that this coupling between electric and rheologic properties need to be taken into consideration when designing the EHD specialized ink.