Estimation of various scattering parameters and 2-DEG mobilities from electron mobility calculations in the three conduction bands Γ, L and X of gallium arsenide

Abstract

The electron drift mobility in Γ conduction band of GaAs has been calculated before, but for the first time, we have made attempts to estimate the electron mobilities in higher energy L and X minima. We have also calculated the value of mobility of two-dimensional electron gas needed to predict hetero-structure device characteristics using GaAs. Best scattering parameters have been derived by close comparison between experimental and theoretical mobilities. Room temperature electron mobilities in Γ, L and X valleys are found to be nearly 9094, 945 and 247 cm2/V-s respectively. For the above valleys, the electron masses, deformation potentials and polar phonon temperatures have been determined to be (0.067, 0.22, 0.39m 0), (8.5, 9.5, 6.5 eV), and (416, 382, 542 K) as best values, respectively. The 2-DEG electron mobility in Γ minimum increases to 1.54 × 106 from 1.59 × 105 cm2/V-s (for impurity concentration of 1014 cm−3) at 10 K. Similarly, the 2-DEG electron mobility values in L and X minima are estimated to be 2.28 × 105 and 1.44 × 105 cm2/V-s at 10 K, which are about ∼4.5 and ∼3.9 times higher than normal value with impurity scattering present.