III-nitride light-emitting diode with embedded photonic crystals

A photonic crystal has been embedded within an InGaN/GaN light-emitting diode structure via epitaxial lateral overgrowth of a p-type GaN capping layer. The photonic crystal is a hexagonal-closed-packed array of nano-pillars patterned by nanosphere lithography; the capping layer planarizes the disconnected pillars to form a current-injection device. Optical properties of the nanostructures and devices are extensively studied through a range of spectroscopy techniques and simulations. Most significantly, the emission wavelengths of embedded photonic crystal light-emitting diodes are nearly invariant of injection currents, attributed to partial suppression of the built-in piezoelectric in the quantum wells. (C) 2013 AIP Publishing LLC.