Characterization of GaN grown by RF plasma MBE

GaN (Gallium nitride) has been grown successfully on sapphire by RF plasma MBE through optimizing the growth condition. Two dimensional triple axis mapping (TDTAM) was used to characterize the GaN epilayers. The dislocation density in the epilayers was estimated to be about 7.8×108 cm−2 according to the mosaic model. The 77K photoluminescence (PL) of the Si-doped GaN with different concentration show that Si can act both donor and acceptor at very high concentration. Transmission spectrum has also been measured for further understanding of the sample.