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

We describe 5 μm squircle InGaN-based red, green, and blue (RGB) monochromatic micro-light-emitting diodes (μLEDs) with an interpitch of 4 μm 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 μLEDs exhibited a broader full width at half-maximum and larger peak wavelength blueshift at 11.5–115 A/cm$^2$ than the green/blue μLEDs. The on-wafer light output power density of the red μLEDs 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 μLEDs. This value was comparable with that of the green/blue μLEDs at 11.5 A/cm$^2$, indicating that the red μLEDs can satisfy the requirement of high brightness levels for specific displays. The color gamut based on InGaN RGB μLEDs covered 83.7% to 75.9% of the Rec. 2020 color space in the CIE 1931 diagram at 11.5 to 115 A/cm$^2$.