Influence of p-GaN shape on the light emission characteristics of InGaN nanodisk embedded p-i-n GaN nanorods

Abstract

InGaN nanodisk embedded GaN nanorods (NRs) with different p-GaN morphologies were grown on Si(111) substrate by plasma-assisted molecular beam epitaxy. Tapered and non-tapered p-GaN top was obtained by varying the growth conditions namely growth temperature and N-2 plasma power, and the morphology evolution was explained based on the interrelation between sidewall diffusion and direct impingement during the NRs growth. Photoluminescence measurements revealed higher light emission for tapered p-GaN when compared to non-tapered structure. APSYS simulations were further conducted to theoretically confirm the observed experimental results. Our results indicate that the fabrication of InGaN-GaN multi-quantum well NRs light emitting diodes (LEDs) with tapered top p-GaN will be a promising approach for the realization of high brightness LEDs. (C) 2015 Elsevier B.V. All rights reserved.