Ultra-small InGaN green micro-light-emitting diodes fabricated by selective passivation of p-GaN

Here, we proposed fabricating ultra-small InGaN-based micro-light-emitting diodes (mu LEDs). The selective p-GaN areas were intentionally passivated using a H-2 plasma treatment and served as the electrical isolation regions to prevent the current from injecting into the InGaN quantum wells below. Three kinds of green mu LEDs, two squircle shapes with widths of 5 and 4 mu m and one circular shape with a diameter of 2.7 mu m, were successfully realized. The currentvoltage characteristics indicate that the series resistance and the turn-on voltage increase as the dimension of the mu LED decreases. This originates from the diffusion of the hydrogen atoms into the unexpected conductive p-GaN area. The light output power density and the calculated external quantum efficiency of the mu LEDs from a 5-mu m-squircle to a 2.7-mu m-circle were enhanced by 10 20% when compared to 98 x 98 mu m(2) mu LEDs that were fabricated using mesa etching. (C) 2021 Optical Society of America