Surface Study of P-Type MBE Gallium Nitride Growth over CdSe Quantum Dots

The objective of our current work is to observe the effects of MBE p-GaN growth over II-VI semiconductor nanocrystals on an MOCVD n-GaN template. The starting material was approximately 2 microns of n-type GaN MOCVD material atop a sapphire wafer. CdSe quantum dots were applied through drop and spin casting. A p-type MBE GaN layer of 2500 A was grown using a nitrogen plasma source. MBE allowed precise growth while SIMS analysis showed the relatively low temperature associated with this method, versus MOCVD, preserved the quantum dots. The surface was investigated using atomic force microscopy in tapping mode for samples at various high/low substrate and magnesium cell temperatures.