Controlling rheological properties of inks for developing high-resolution 264 ppi all inkjet-printed QD-LED display

Abstract

Inkjet printing (IJP) technology enables high-precision color patterning for quantum dot light-emitting diode (QD-LED) displays, but there are many technological challenges to achieving high pixel densities. Especially, the compatibility between ink properties and inkjet printing processes is crucial for high-resolution display. Here, we developed advanced inkjet printing processes for fabricating high-resolution 264-ppi QD-LED displays. The analysis and optimization of rheological properties of inks for printing charge transporting layers and QD emissive layers have been studied using a piezo axial vibrator (PAV) which provides useful rheological information for inkjet printing. In addition, post-inkjet processes, such as drying and thermal baking, are optimized to produce high-performance devices. This work demonstrates that the IJP is a promising technology for cost-effective large-scale production of high-quality QD-LED displays suitable for high-quality TVs, monitors, and IT products including tablets and laptops.