Nanoporous Nitrogen-Ion-Implanted InGaN Resonant-Cavity Light-Emitting Diodes for Vertical-Cavity Surface-Emitting Lasers

Abstract

InGaN resonant-cavity light-emitting diodes (RC-LEDs) with a dielectric distributed Bragg reflector (DBR), a porous-GaN DBR, and a nitrogen ion (N + )-implanted aperture (6 μm diameter) were demonstrated. In the ion implantation process, the N + ions were penetrated directly through an indium-tin-oxide conductive layer and SiO 2 layer to form the insulated p-GaN:Mg layer, which provides a fascinating current confinement structure. The broadened electroluminescence (EL) peaks were measured at 401.5 and 435.8 nm in the implanted LED without double DBR structures. Multiple EL emission peaks with narrow line widths were observed in the RC-LED structure, indicating a strong resonant effect with different cavity modes. Two groups of effective resonant-cavity lengths, 1.48 and 1.50 μm, were analyzed through the angle-resolved EL spectra due to the anisotropic porous-GaN layers in the porous DBR structure. The divergent angles in far-field EL radiation patterns were reduced from 118°for the nontreated LED to 28°for the RC-LED structures. A high resonant-cavity effect, line-width narrowing phenomenon, and small divergent angle were observed in the InGaN RC-LED with 6 μm-diameter ion-implanted aperture and top dielectric/bottom porous DBR structures.