Sub-Micron Monolithic Full-Color Nanorod LEDs on A Single Substrate

The extended reality (XR) display, including augmented reality (AR) and virtual reality (VR), requires ultrahigh-resolution and high-luminance pixel technology. GaN-based micro-LEDs are the most promising for high-density pixel applications. However, it is necessary to simultaneously fabricate full-color R/G/B emitters on a single substrate. Moreover, the efficiency droop at long wavelengths with high-indium InGaN still remains a challenge. The InGaN nanorod has the potential to realize monolithic R/G/B LEDs on a single substrate, and the Al reflector has a light reflectance that can dramatically improve light extraction efficiency. Here, we designed sub-micron monolithic full-color R/G/B nanorod LEDs with an Al core-shell reflector on single chip. The optimal structures for light confinement and vertical light extraction by single InGaN nanorod R/G/B LED structures were identified. The single nanorod with Al core-shell structure dramatically increased the light extraction efficiency, and showed an improvement of more than 20%, especially in the red wavelength. As a result, by introducing a long-length nanorod structure, we have successfully designed a new submicron pixel with full-color R/G/B LEDs operating within 1 μm × 1 μm size. This unique design will be a key factor in enabling the next generation of AR and VR displays that require ultra-small and compact pixels.