Monolithic Integration of InGaN-Based Nanocolumn Light-Emitting Diodes with Different Emission Colors

We demonstrate the monolithic integration of green and orange InGaN-based nanocolumn light-emitting diodes (LEDs). Four nanocolumn LED crystals (LEDs 1 to 4), which consisted of regularly arranged InGaN-based nanocolumns in a triangular lattice of 400 nm lattice constant, were grown on the same GaN template on a (0001) sapphire substrate, with designed nanocolumn diameters D of 150, 190, 230, and 270 nm for LEDs 1-4, respectively. LEDs 1 to 3 operated under DC current injection at room temperature, emitting at 544, 583, and 597 nm, respectively. This experiment paves the way for the monolithic integration of three-primary-color nanocolumn LEDs. (C) 2013 The Japan Society of Applied Physics