Vertical GaN-On-GaN Micro-LEDs for Near-Eye Displays.

Abstract

In various micro-light-emitting diode (micro-LED) display products, near-eye applications such as AR (augmented reality) and VR (virtual reality) are gaining popularity, driving consumer demand for higher brightness, resolution, and compact size. To address more advanced demands, GaN-on-GaN homoepitaxial micro-LEDs are notable for their low defect density, excellent thermal management, high efficiency, etc. Additionally, the conductivity of the GaN substrate enables the efficient integration of vertical micro-LEDs, further enhancing performance for near-eye displays. In this work, GaN-on-GaN homoepitaxial platforms to fabricate low-defect-density micro-LEDs are leveraged with superior electrical properties, addressing the limitations of conventional heterogeneous substrates. By replacing traditional ICP (Inductively coupled plasma) mesa etching with fluorine ion implantation for pixel isolation, this study achieves significant reductions in series resistance and enhances optical performance, characterized by sharper pixel edges and a narrowed full width at half maximum (FWHM). Furthermore, the implementation of vertical micro-LED architectures enables a compact device footprint, facilitating ultra-dense integration for near-eye systems. To evaluate performance under practical operating conditions, the effective external quantum efficiency (EQE_effective) is introduced. The ion-implanted vertical structures demonstrate a substantial improvement in EQE_effective over traditional ICP-etched devices, underscoring their potential for high-brightness applications. This work advances high-resolution, energy-efficient micro-LED technologies, offering a scalable pathway for next-generation AR/VR displays.