Growing an improved P-GaN layer of an LED through pressure ramping

A light-emitting diode (LED), comprising:

• a substrate;
• a p-doped III-V compound layer and an n-doped compound layer each disposed over the substrate;
• and
• a multiple quantum well (MQW) layer disposed between the p-doped III-V compound layer and the n-doped III-V compound layer, wherein a disposition of the MQW layer relative to the p-doped III-V compound layer allows a dopant from the p-doped III-V compound layer to diffuse into the MQW layer,
• wherein the p-doped III-V compound layer and the n-doped III-V compound layer are free of having a capping layer therebetween,
• wherein the p-doped Ill-V compound layer includes a first region having an approximately linear doping concentration characteristic and a second region having an exponential doping concentration characteristic,
• wherein the first region of the p-doped compound layer is adjacent to the MQW layer,
• wherein the first region is defined from a first surface of the p-doped III-V compound layer,
• wherein the second region is defined from a second surface of the p-doped III-V compound layer opposite the first surface, and
• wherein a part of the second region at the second surface of the p-doped III-V compound layer has a greatest doping concentration and wherein a doping concentration level of the p-doped III-V compound layer continuously decreases from the second surface to the first surface.

A device, comprising:

• a first doped gallium nitride layer;
• a multiple quantum well (MQW) layer disposed over the first doped gallium nitride layer;
• a second doped gallium nitride layer disposed directly on the MOW layer, wherein the second doped gallium nitride layer includes a first portion with an approximately linear doping profile and a second portion with an approximately exponential doping profile, and wherein the first portion is adjacent to the MQW layer, and wherein a disposition of the MQW layer relative to the second doped gallium nitride lam allows a dopant from the second doped gallium nitride layer to diffuse into the MQW layer;
• and
• a metal layer bonded to the second portion of the second doped gallium nitride layer, wherein the second portion has a greatest doping concentration level at an interface between the second portion and the metal layer, wherein a doping concentration level of the second doped gallium nitride layer continuously decreases from a first surface of the second doped gallium nitride layer bonded to the metal layer to a second surface of the second doped gallium nitride layer opposite the first surface.