Embodiments relate to semiconductor structures and methods of forming them. In some embodiments, the methods may be used to fabricate semiconductor structures of III-V materials, such as InGaN. An In-III-V semiconductor layer is grown with an Indium concentration above a saturation regime by adjusting growth conditions such as a temperature of a growth surface to create a super-saturation regime wherein the In-III-V semiconductor layer will grow with a diminished density of V-pits relative to the saturation regime.