Effect of surfactant Sb on In incorporation and thin film morphology of InGaN layers grown by organometallic vapor phase epitaxy

•InGaN thin films were grown by OMVPE using different concentrations of Sb surfactant.•PL emission peak energy of InGaN shifted abruptly at a critical Sb concentration.•A corresponding change in morphology occurred at the critical Sb concentration.•Addition of Sb changed InGaN bandgap and increased In incorporation from 18% to 31%.•We report evidence of a surfactant-induced change of surface phase on InGaN films.

The effects of the surfactant Sb on InGaN grown by organometallic vapor phase epitaxy (OMVPE) were studied. Eight samples of InGaN were grown with Sb concentrations ranging from 0% to 2.5%. Characterization was done by photoluminescence (PL) and atomic force microscopy (AFM). An abrupt change in PL emission peak energy and surface morphology occurred at a certain critical Sb concentration. Above and below this threshold concentration two distinct regimes of surface morphology and PL emission characteristics were observed. This effect was interpreted as due to a surfactant-induced change of surface phase on the InGaN films.