Full-color quantum dots active matrix display fabricated by ink-jet printing

Abstract

Making full-color active matrix display based on quantum dot light emitting diodes (AM-QLEDs) via ink-jet printing is attractive in display industry due to QLEDs’ wide color gamut and their potential manufacturing advantages of large screen size and low cost. The challenges for realizing AM-QLED display are how to achieve high quality films through ink-jet printing, multi-color patterning, electroluminescence (EL) color purity, and high efficiency. Herein, a 2-inch diagonal full-color AM-QLEDs display with pixel density of 120 pixels per inch (PPI) fabricated by ink-jet printing technique is presented. Driven by a metal oxide TFT (MOTFT) back-panel, the display exhibits a maximum brightness of 400 cd m−2, and a color gamut of 109% (NTSC 1931). The red, green, and blue (RGB) monochrome QLEDs passive matrix panels fabricated by ink-jet printing technique have a current efficiency (CE) of 2.5, 13.9, and 0.30 cd A−1, respectively. To the best of our knowledge, the efficiencies are the highest among passive matrix QLEDs panels made by ink-jet printing technique. The ink-jet printed QDs films show good thickness uniformity due to high viscosity and low volatility of the printable inks, and no cross-contamination between adjacent pixels resulting from the hydrophobic pixel defining layer.