This study examined the effects of (5, 10) pair of Al1-xGaxN/GaN superlattices based (25, 50 nm) HT-AlN on the optical properties and crystallinity of GaN pyramids and InGaN/GaN multiple quantum wells. High resolution X-ray diffraction revealed 10-pair of Al1-xGaxN/GaN superlattices on a 50 nm HT-AlN buffer layer to have the narrowest full width at half maximum of 1.215 degrees because the Al1-xGaxN/GaN superlattices prevent the dislocations generated at the interface between the AlN buffer layer and Si substrates from propagating to the surface of GaN. The optical properties and emission region of InGaN/GaN multiple quantum wells on the GaN pyramids were observed by photoluminescence and cathodoluminescence measurements.

Keywords: High resolution X-ray diffraction; Superlattices; Selective epitaxy; Nitride; Semiconducting III-V materials