Low-field electron mobility in bulk AlGaN

Abstract

The low-field electron drift mobility at 300 K has been calculated as a function of electron density for bulk AlxGa1-xN, taking into account the two-mode nature of the alloy. The interaction with acoustic modes via the piezoelectric effect or by the deformation potential was taken to be statically screened. Alloy scattering in the polar-fluctuation model was shown to be negligible. The effects of impurity and dislocation scattering were ignored in order to obtain upper limits: 1300 cm2/Vs for GaN and 877 cm2/Vs for Al0.3Ga0.7N with n = 1016 cm-3.