Porous GaN Nanopyramids: Advancing Beyond Conventional Nanostructures for High‐Brightness InGaN/GaN Quantum Wells Emission

Abstract

GaN nanostructures hold significant promise in advancing nanoscale light‐emitting devices. However, significant progress remains elusive, possibly due to the absence of innovative approaches. Beyond the smaller size of GaN nanostructures, the main interest lies in growing InGaN active layers on semi‐ and non‐polar orientations. Nevertheless, it is evident that while leveraging such a method holds initial promise, this approach may eventually reach its limits, prompting the need for fresh perspectives. In this manuscript, electrochemical etching is utilized to fabricate porous GaN nanopyramids. Given the absence of prior studies on electrochemical etching of GaN nanostructures, its etching behavior is investigated, revealing its selectivity concerning doping concentration and geometry. Furthermore, how the choice of electrolyte can differently impact the optical response of the etched template is explored. Subsequently, an InGaN/GaN quantum wells shell is grown as the active region. The significance of the approach is evidenced by a tenfold enhancement in photoluminescence emission. Porous nanopyramids demonstrate a higher internal quantum efficiency of 44.7% and faster radiative recombination time. Additionally, finite difference time domain simulation reveals a twofold increase in light extraction efficiency. This research will lead the way toward the development of a new class of nanostructures offering potential advancements in optoelectronic devices.