Efficient current injection scheme for nitride vertical cavity surface emitting lasers

The authors report the realization of $\mathrm{In}\mathrm{Ga}\mathrm{N}∕\mathrm{Ga}\mathrm{N}$ light emitting diodes (LEDs) with an electrical injection design suitable for vertical cavity surface emitting lasers. Controlled oxidation of an AlInN interlayer lattice matched to GaN allows confining the injected current in a $3\mu \mathrm{m}$ diameter aperture. Submicron-scale characterization of the current flow and optical properties is achieved by means of microelectroluminescence measurements. LEDs can be safely driven, in continuous mode operation, up to current densities higher than $20\mathrm{kA}∕{\mathrm{cm}}^2$ .