The formation of In-rich regions at the perphery of the inverted hexahonal pits of InGaN thin-films grown by metalorganic vapor phase epitaxy

InGaN thin films were grown by low-pressure metalorganic-vapor-phase-epitaxy (MOVPE) and characterized by cathodoluminescence (CL) and scanning electron microscopy(SEM). SEM images showed that InGaN samples have inverted hexagonal pits which are formed by the In segregation on the (10(1) over bar1) surfaces. Room temperature CL at the wavelengths corresponding to the GaN band edge, the In-poor and In-rich regions showed that the In-rich regions formed at the periphery of the hexagonal pits.