Abstract
The authors demonstrate the coalescence overgrowth of GaN nano-columns on a (111) Sisubstrate with metalorganic chemical vapor deposition to show high-quality opticalproperties in the overgrown film. Plan-view scanning electron microscopy (SEM) showscoalesced surface morphology, although hexagonal structures are still visible in the images.The cross-section cathodoluminescence (CL) image shows more efficient emission in theovergrowth layer than from the nano-column layer. The plan-view CL image demonstratesthat the emitted light is mainly from the hexagonal structures. The photoluminescencemeasurement result indicates that the emission efficiency of the overgrown layer is evenhigher than that of an undoped GaN thin film of high quality. The presence of hexagonalstructures correlates to surface roughness values in the range of several nanometres.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
