Abstract

We report a detailed study of the growth of InGaN by plasma assisted molecular beam epitaxy. The In composition is around 55% providing the optimum bandgap in the near-infrared spectral region of the matrix material of quantum dot (QD) intermediate band solar cells. The layer thickness is 80 nm for sufficient absorption. Optimum growth conditions are identified at elevated N flux and reduced growth temperature for minimized phase separation and smooth surface morphology. On these optimized InGaN layers, InN QDs are grown exhibiting small size and high density. Optical emission is observed from both the InGaN layer and InN QDs.