Light emitting diodes based on GaN core/shell wires grown by MOVPE on n-type Si substrate

A report is presented on the fabrication of light emitting diodes (LEDs) based on GaN core/shell wires on conductive substrates by metal organic vapour phase epitaxy. Catalyst-free GaN-based wires are grown spontaneously on 2-inch n-doped silicon substrates without any thick buffer layer. The LED wire heterostructure consists of an n-type GaN:Si core covered radially by five InGaN/GaN quantum wells and a p-type GaN:Mg shell. Macroscopic devices that integrate around 10⁶ wire-LEDs have been obtained thanks to a simple, direct and full-wafer scale contacting process. For the first time, continuous-wave electrical injection at room temperature through the Si substrate into a cm²-chip of GaN-based core/shell wire-LEDs is successfully demonstrated, producing blue electroluminescent emission at 450 nm.