A model for single heterostructure field effect transistors

Single heterostructure field effect transistors are studied within a proposed analytical model for the heterostructure conduction band potential profile. An expression for the bias potential closing the conduction channel between drain and source is derived as a function of growth parameters and bias. In particular we study a field effect transistor based on Al_xGa_1−xN/GaN. The quantum well potential is modelled along the lines of the local density Thomas-Fermi approximation with the inclusion of exchange effects. Recent experimental results on two-dimensional electron gas density in this kind of systems are explained.