GaN microcavity structure with dielectric distributed Bragg reflectors fabricated by using a wet-chemical etching of a (111) Si substrate

GaN microcavity structure with SiO₂/ZrO₂ dielectric distributed Bragg reflectors was fabricated by means of transferring an InGaN/GaN multiple quantum well (QW) structure from the (111) Si substrate onto a sapphire carrier and wet-chemical etching of the substrate. A dip in the reflectivity spectrum of the microcavity structure is observed at a wavelength of 411 nm indicating the cavity resonance mode. Also, the strong influence of the cavity on the QW photoluminescence has been observed. A sharp emission spectrum, with a linewidth of 3.5 nm, occurs at a wavelength of 411 nm coincided with the position of the cavity resonance mode.