Investigation of facet-dependent InGaN growth for core-shell LEDs

摘要

In this work we used vertically aligned GaN nanowires with well-defined crystal facets, i.e. the {11-20} a-plane, {10-10} m-plane, (0001) c-plane and {1-101} semi-polar planes, to investigate the impact of MOVPE reactor parameters on the characteristics of an InGaN layer. The morphology and optical characteristics of the InGaN layers grown of each facet were investigated by cathodoluminescence (CL) hyperspectral imaging and scanning electron microscopy (SEM). The influence of reactor parameters on growth rate and alloy fraction were determined and compared. The study revealed that pressure can have an important impact on the incorporation of InN on the {10-10} m-plane facets. The growth performed at 750℃ and 100mbar led to a homogeneous high InN fraction of 25% on the {10-10} facets of the nanowires. This work suggests homogeneous good quality GaN/InGaN core-shell structure could be grown in the near future.