Highly Enhanced Light Recycling in Quantum Dot Displays by Sidewall Reflectors

Quantum dot (QD) color conversion‐based displays have emerged as one of the most promising next‐generation devices due to their superior emission properties in terms of color expression. To date, however, existing QD color conversion layer (QD‐CCL) technologies have suffered from low luminance and power efficiency, mainly due to significant light absorption by the bank structure. Here, the color conversion efficiency of QD‐CCL has been significantly enhanced by fabricating a highly reflective metal layer on the side surface of the bank structure. Using a high‐aspect‐ratio silver reflector fabricated through a secondary sputtering lithographic technique involving argon ion bombardment, the fabricated QD‐CCL is combined with a blue organic light‐emitting diode (OLED) serving as a light source. As a result, light recycling from the reflector significantly enhances color conversion efficiency and luminance by up to 4.60‐fold and 4.29‐fold, respectively. Optical simulation reveals that higher pixel resolution provides greater reflection probabilities during extraction. This photomask‐free approach is not only simple but also highly compatible with existing semiconductor fabrication processes, making it a viable commercial alternative for all color‐converting structures that utilize light‐emitting materials with omnidirectional emission characteristics.