Enhanced ultraviolet GaN photo-detector response on Si(111) via engineered oxide buffers with embedded Y2O3/Si distributed Bragg reflectors

Abstract

Based on a virtual GaN substrate approach on Si(111) by a step graded double oxide (Sc2O3/Y2O3) buffer, we report a proof of principle study on the enhanced photo-response of ultraviolet GaN photo-detectors due to embedded DBRs (distributed Bragg reflectors). Embedded DBRs benefit from an order of magnitude lower number of superlattice sequences in contrast to III- nitride systems due to the high refractive index contrast between high-k Y2O3 and low-k Si. The UV (ultraviolet) reflectance efficiency of the designed DBR is proven by a considerable photo-response increase in the UV range in comparison to reference GaN layers on Si(111) without DBRs. © 2014 AIP Publishing LLC.