Advances in InGaN/GaN Nanocolumns for Micro-LED Displays

Abstract

  Using InGaN/GaN-ordered nanocolumn (NC) arrays, two-dimensionally arranged multicolor (blue, green, yellow, and red) NC micro-LED (μLED) pixels with a luminous area of 5×5 μm² were demonstrated, exhibiting attractive prospects for application in μLED displays. The red μLED pixel exhibited low light intensity with a broad emission spectrum. To improve the red luminous property, semipolar InGaN/AlGaN multiple-quantum-wells were integrated into NC LED crystals, thereby realizing a φ2.2 μm red NC μLED with a high on-wafer external quantum efficiency of 2.1%. Additionally, honeycomb-lattice NC plasmonic crystals were investigated, which demonstrated a 4.8-fold enhancement of red light emission. Photonic crystal (PhC) NC LEDs exhibited directional light beam radiation and wavelength stability against current changes, with red wavelength stability at 615 nm. The monolithic integration of multicolor (green to orange) PhC NC LEDs was demonstrated. These results are promising for the development of three primary colors (RGB) integrated NC LEDs as next-generation full-color LEDs.