Two-dimensional electron gas mobility limited by barrier and quantum well thickness fluctuations scattering in AlxGa1-xN/GaN multi-quantum wells

We calculate the electron mobility limited by the AlxGa1-xN barrier and the GaN well thickness fluctuations scattering of the two-dimensional electron gas (2DEG) at AlxGa1-xN/GaN multi-quantum wells (MQWs) with a triangle potential well. For this potential well, the ground subband energy is governed by the spontaneous and piezoelectric polarization fields and the fields are determined by the barrier and well thicknesses in undoped AlxGa1-xN/GaN MQWs. Thus, the thickness fluctuations of AlxGa1-xN barrier and GaN well will cause a local fluctuation of the ground subband energy, which will reduce the 2DEG mobility. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4704142]