P‐135: Light Recycling in Quantum‐Dot Organic Light‐Emitting Diode Using Side‐Wall Reflector Formed by a Secondary Sputtering Lithographic Technique

In quantum dot‐organic light‐emitting diode (QD‐OLED), the emission from the blue OLED is absorbed by QDs and re‐emitted to implement green and red subpixels. To prevent optical crosstalk between pixels, black matrices (BMs) are utilized. During the color conversion process, re‐emitted light is released in random directions. If a reflective layer is formed on the BMs, the light can either be reabsorbed by the QD layer for reuse or emitted externally without being lost in the BM layer. In this study, a BM structure was directly formed on the blue OLED and a secondary sputtering lithographic technique was used to fabricate reflective side‐walls. The process was conducted without damaging the OLED device. By forming the QD layer between the reflective walls, a 20% improvement in color conversion efficiency was observed compared to when reflective walls were not used.