Buried Dielectric Mirrors for the Lateral Overgrowth of GaN-Based Microcavities

The use of lateral overgrowth techniques to develop III-nitride microcavities with both mirrors fabricated from very highly reflecting dielectric multilayers (e.g. SiO2/ZrO2) will be discussed. Multilayer mirror stacks with broad high reflectivity stop-bands and peak reflectivities in excess of 99% at wavelengths near the emission energies of typical InGaN/GaN quantum well structures, have been patterned in order to be compatible with subsequent lateral epitaxial overgrowth or pendeoepitaxy. Improvements in material quality resulting from lateral overgrowth above single layer masks are demonstrated using spatially resolved photoluminescence and cathodoluminescence imaging.