Ultrasmall and ultradense InGaN-based RGB monochromatic micro-light-emitting diode arrays by pixilation of conductive p-GaN

We describe 5 mu m squircle InGaN-based red, green, and blue (RGB) monochromatic micro-light-emitting diodes (mu LEDs) with an interpitch of 4 mu m by pixilation of conductive p-GaN using a H-2-plasma treatment. The p-GaN was passivated by H-2 plasma and prevented the current's injection into the InGaN quantum wells below. We observed that InGaN-based red mu LEDs exhibited a broader full width at half-maximum and larger peak wavelength blueshift at 11.5-115 A/cm(2) than the green/blue mu LEDs. The on-wafer light output power density of the red mu LEDs at a wavelength of 632 nm at 115 A/cm(2) was approximately 936 mW/cm(2), the highest value reported thus far for InGaN-based red mu LEDs. This value was comparable with that of the green/blue mu LEDs at 11.5 A/cm(2), indicating that the red mu LEDs can satisfy the requirement of high brightness levels for specific displays. The color gamut based on InGaN RGB mu LEDs covered 83.7% to 75.9% of the Rec. 2020 color space in the CIE 1931 diagram at 11.5 to 115 A/cm(2). (C) 2021 Chinese Laser Press

Automated summary

In this study, 5 μm squircle InGaN-based red, green, and blue monochromatic micro-light-emitting diodes were successfully fabricated with a 4 μm interpitch using a H-2-plasma treatment for pixilation of conductive p-GaN. The red mu LEDs exhibited broader full width at half-maximum and larger peak wavelength blueshift at high current densities, showing high on-wafer light output power density and coverage of a wide color gamut based on InGaN RGB technology.