Abstract
We report on the temperature dependence of the mobility, μ, of the two-dimensional electron gas in a variable density AlGaN/GaN field effect transistor, with carrier densities ranging from 0.4×1012 cm−2 to 3.0×1012 cm−2 and a peak mobility of 80,000 cm2/Vs. Between 20 K and 50 K we observe a linear dependence μ−1ac=αT indicating that acoustic phonon scattering dominates the temperature dependence of the mobility, with α being a monotonically increasing function of decreasing 2D electron density. This behavior is contrary to predictions of scattering in a degenerate electron gas, but consistent with calculations which account for thermal broadening and the temperature dependence of the electron screening. Our data imply a deformation potential D = 12-15 eV.
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URL
https://arxiv.org/abs/cond-mat/0503638