Electronic and optical properties of hybrid GaN/por-Si(111) heterostructures

Abstract

Using plasma-assisted molecular beam epitaxy (PA MBE) of nitrogen, we obtained integrated heterostructures based on a self-ordered array of GaN nanocolumns on Si substrates with a sufficiently uniform distribution of diameters, which subsequently coalesced into a 2D layer. The use of a ‘compliant’ por-Si substrate for GaN synthesis using PA MBE allowed us to obtain a crack-free GaN layer, prevent the Ga-Si etching process, maintain a sharp smooth Si – GaN interface, and also partially suppress the generation of tensile stresses caused by cooling the heterostructure from growth temperature to room temperature by its relaxation at the Si – GaN nanoporous interface, which had a positive effect on its optical properties in the UV region.