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

•InGaN embedded p-i-n GaN nanorods prepared by plasma-assisted molecular beam epitaxy.•Effect of top p-GaN tapering on the light emission properties of nanorods investigated.•PL spectra showed enhanced light emission for p-i-n GaN nanorods with tapered p-GaN.•Theoretical analysis using APSYS simulations are consistent with experimental results.

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 N2 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.

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