Growth and characterization of modulation-doped AlxGa1-xN/GaN heterostructures

The modulation-doped Al-0.22 Ga0.78N/GaN heterostructures with different Al 0.22Ga0.78N barrier thicknesses were grown by means of metal-organic chemic al vapour deposition. The Al-0.22 Gao.7sN layer still has pseudomorphic gro wth when its thickness is 53nm. The mobility of the two-dimensional electro n gas (2DEG) at the heterointerfaces is much higher than that of the electr ons in GaN films at both 300 and 77K. The dramatic decrease of the 2DEG mob ility in an Al0.22Ga0.78N/GaN heterostructure corresponds to the partial re laxation of the Al0.22Ga0.78N barrier.