Effects of growth interruption on high indium content InGaN/GaN multi quantum wells

The effects of the growth interruption time on the optical and title struct ural properties have been investigated. The high indium content InxGa1-xN/G aN (x > 0.25) multi quantum wells used in this study were grown on c-plane sapphire by using metalorganic chemical vapor deposition. The interruption was carried out by closing tile group-III metal organic sources before and after the growths of the InGaN quantum well layers. With increasing interru ption time, the quantum dot like? region and well thickness decreased due t o indium re-evaporation or the thermal etching: effect. As a result, the PL peak position was blue-shifted, and the intensity was reduced. The sizes a nd the number of V-defer:ts did not differ with the interruption time. The interruption time was not directly related to the formation of defects. The V-defects originate at threading dislocations and inversion domain boundar ies due to higher misfit strain.