Low-temperature monolithic integration of patterned distributed Bragg reflectors for high-resolution QD-OLED microdisplays

With the increasing demand for hyper-realistic displays, significant advancements have been reported in high-resolution quantum dot–organic light-emitting diode (QD-OLED) technology owing to its wide color gamut and improved color purity. However, achieving both high color purity and light extraction remains a critical challenge due to significant blue light leakage in high resolution QD-OLED. Here, we overcome these limitations by demonstrating a damage-free, low-temperature ( < 100 °C) monolithic integration of patterned distributed Bragg reflectors (DBRs) directly onto a QD-OLED stack to effectively suppress blue leakage and enhance conversion efficiency. DBRs fabricated from SiN x and SiO x using low-temperature ( < 100 °C) plasma-enhanced chemical vapor deposition demonstrate high reflectance of 95.9% at 455 nm while effectively suppressing reflectance in the red and green regions. A high-precision, one-step fluorine-based dry etching process achieved a 4 μm pattern size with a near-vertical taper angle of 89°, supporting pixel densities up to 3175 ppi. Compared to the device without DBR, the monolithically integrated architecture exhibits a photon recycling effect, enhancing red and green emission intensities by 19.7% and 10.7%, respectively, while reducing blue leakage by approximately 90%. Furthermore, the integrated device achieved a color gamut of 120.5% relative to the sRGB standard. These findings confirm that monolithically integrated DBRs serve as a robust and scalable solution for next-generation high-resolution QD-OLED displays.