The influence of the deformation on the two-dimensional electron gas density in GaN-AlGaN heterostructures

We report on the effect of external strain on the two-dimensional electron gas density in AlGaN/GaN heterostructures grown on sapphire by low pressure metalorganic chemical vapor deposition. The electron sheet concentration in the studied samples was 4x10(12)-2x10(13) cm(-2) and decreased with compressive strain. Lower doped heterostructures had a higher sensitivity to applied strain. The comparison between the experimental data and our model shows that the GaN layers are primarily nitrogen terminated at the heterointerface. (C) 1998 American Institute of Physics.