InGaN platelets: synthesis and applications towards green and red light emitting diodes

In this work, we present a method to synthesize arrays of hexagonal InGaN sub-micron-platelets with a top c-plane area having an extension of a few hundred nanometers by selective area metal organic vapor phase epitaxy. The InGaN platelets were made by in-situ annealing of InGaN pyramids, whereby InGaN from the pyramid apex was thermally etched away, leaving a c-plane surface, while the inclined {101 1} planes of the pyramids were intact. The as-formed c-planes, which are rough with islands in a size of a few tens nanometers, can be flattened with InGaN regrowth, showing single bilayer steps and high-quality optical properties (full width at half maximum of photoluminescence at room temperature: 107 meV for In0.09Ga0.91N and 151 meV for In0.18Ga0.82N). Such platelets offer surfaces having relaxed lattice constants thus enabling shifting the quantum well emission from blue (as when grown on GaN) to green and red. For single InGaN quantum wells grown on the c-plane of such InGaN platelets, a sharp interfac...