Microdisks incorporating InGaN quantum dots were fabricated using SiO2 microspheres as a hard mask in conjunction with a photo-electrochemical etch step from a structure containing a sacrificial InGaN/InGaN superlattice. Formation of microdisks from two near-identical structures with differing dislocation densities was carried out and investigated using microphotoluminescence. This confirmed the existence of quantum dots through the presence of resolution limited spectral lines and showed a clear correlation between the resulting modes quality factors and the dislocation densities within the disks. The disks with higher dislocation densities showed up to 80% lower quality factors than the low dislocation density disks.

Dislocation Density-Dependent Quality Factors in InGaN Quantum Dot Containing Microdisks. H.A.R.El-Ella, F.Rol, M.J.Kappers, K.J.Russell, E.L.Hu, R.A.Oliver: Applied Physics Letters, 2011, 98[13], 131909