Large-area patterning of full-color quantum dot arrays beyond 1000 pixels per inch by selective electrophoretic deposition.

Colloidal quantum dot (QD) emitters show great promise in the development of next-generation displays. Although various solution-processed techniques have been developed for nanomaterials, high-resolution and uniform patterning technology amicable to manufacturing is still missing. Here, we present large-area, high-resolution, full-color QD patterning utilizing a selective electrophoretic deposition (SEPD) technique. This technique utilizes photolithography combined with SEPD to achieve uniform and fast fabrication, low-cost QD patterning in large-area beyond 1,000 pixels-per-inch. The QD patterns only deposited on selective electrodes with precisely controlled thickness in a large range, which could cater for various optoelectronic devices. The adjustable surface morphology, packing density and refractive index of QD films enable higher efficiency compared to conventional solution-processed methods. We further demonstrate the versatility of our approach to integrate various QDs into large-area arrays of full-color emitting pixels and QLEDs with good performance. The results suggest a manufacture-viable technology for commercialization of QD-based displays.