Perovskite Quantum Dot Color Conversion Pattern Fabricated by an In-situ Inkjet Printing

Abstract

Inkjet printing technology has broad application prospects in the manufacture of optoelectronic devices due to its advantages of mask-free and high material utilization. However, the coffee ring effect during printing can make the morphology non-uniform and has not been thoroughly explored. In this work, we used a high-precision in-situ inkjet printing system to print low-viscosity perovskite precursor inks on substrates to generate color-converting films. The viscosity of the perovskite precursor solution was improved by changing the ratio of the 5-AVABr additive, coupled with the choice of DMF with a higher boiling point as the solvent, which greatly reduced the evaporation of the solvent at the edge of the droplet, driving the formation of Marangoni flow which can result a uniform surface of droplets, culminating in a microarray of coffee-free rings. Notably, the perovskite can be crystallized in situ during printing without additional annealing, relying on a pumping system to assist the solvent evaporation.With the additive, the photoluminescence quantum yield of the film increased to 39%. The size of each pixel in microarrays was controlled to be less than 60 μm and 400 pixels per inch (PPI) is realized. Our work paves the way for large-area, high-efficiency production of perovskite color conversion films.