Enhanced performance of vertical-structured InGaN micro-pixelated light-emitting-diode array fabricated using an ion implantation process.

In this Letter, a new approach to fabricating a high-efficiency vertical-structured InGaN micro-pixelated light-emitting diode (µVLED) is presented. The high-resistivity selective areas are intentionally created in the n-GaN layer through a fluorine (F) ion-implantation process and then used as the electrical isolation regions for realizing a µVLED array consisting of 25×25 pixels with a diameter of 10 µm. The results prove that the dual-energy F- ion implantations not only can improve the uniformity of carrier distribution but also can effectively prevent current from leaking along the etched sidewalls, which in turn realize a more efficient carrier injection into the mesa area. More notably, the current-handling capability and corresponding optical output power density of the µVLED array are substantially higher than those of conventional vertical-structured broad-area LEDs. A measured output light power density of the F- ion-implanted µVLED array reaches a maximum value of 43 W cm-2 at 3.06 kA cm-2, before power saturation. The improved luminescence performances of the µVLED array can be attributed to an effective ion-induced heat relaxation and associated lower junction temperature.