Implantation energy- and size-dependent light output of enhanced-efficiency micro-LED arrays fabricated by ion implantation

Abstract

A new process is presented for fabricating enhanced-efficiency micro-pixelated vertical-structured light-emitting diode (µVLED) arrays based on ion-implantation technology. High-resistivity selective regions are locally introduced in the n-GaN layer by ion implantation and then used as effective and non-destructive electrical isolation for realizing µVLED arrays with ultra-small pixel diameters. The implantation energy-dependent and size-dependent opto-electrical characteristics of fluorine (F-) implanted µVLED arrays are investigated systematically. The results show that the optimally designed F- ion implantation not only can achieve smaller reverse leakage current but also can realize ion-induced thermal relaxation effectively and is more suited for fabricating high-resolution µVLED arrays with higher optical output power. For the F--implanted µVLED array with pixel diameters of 10 µm, a measured output power density reaches a value of 82.1 W cm−2 at a high injection current density of 220 A cm−2, before power saturation. Further, the output power densities and external quantum efficiencies of F--implanted µVLED arrays with pixel diameters less than 10µm show strong dependences on pixel size due to the presence of defects-related SRH process. So, the high-efficiency µVLED arrays with ultra-small pixel sizes could be fabricated by an appropriately designed ion implantation combined with control of defect densities to meet the industrial requirement of microdisplay applications.

Ge Ion Implanted Photonic Devices and Annealing for Emerging Applications

“…The ion implantation technique has been widely reported for modification and doping of materials. The performance of devices can, therefore, be improved after this treatment [60][61][62][63][64].…”

Electrically Driven Sub‐Micrometer Light‐Emitting Diode Arrays Using Maskless and Etching‐Free Pixelation

“…[ 13 ] Ion implantation has the advantage that the planar geometry of the LED wafer is maintained after pixelation without exposing any sidewalls; hence, no sidewall leakage current is present. [ 12 ] However, these methods employed hard masks for pixelation and they cause significant lateral penetration of the implanted ions on to the masked region mainly due to ion scattering at the mask edge and subsequent lateral channeling effect, resulting in undesired emission degradation at the edge of pixels. Therefore, the ion implantation with a mask requires specific material and thickness of the mask depending on the implanted ions and implantation conditions, [ 13 ] and needs additional processes for lithography and mask deposition followed by mask removal after the ion implantation.…”

Cavity Mode-Matching InGaN Aperture-Emitting Device with a Nanoporous GaN Reflector via Ion Implantation

“…The optical absorption and refractive index increase in the ion-implanted epitaxial layers have been discussed for the GaN VCSEL devices . To date, the size scaling effects in micro-pixel vertical-structured LED arrays, realizing ultrahigh-density displays for augmented reality glasses, enhancing photoelectric performance, and introducing tunnel junction structure for micro LED arrays operation, have been reported. A recent approach to the N ++ ion implantation method of nanoporous (NP) GaN DBR has been reported for creating high-index-contrast GaN optical structures .…”