Self-Consistent Results for a GaAs/Al_xGa_1−xAs Heterojunciton. II. Low Temperature Mobility

Abstract

The low temperature mobility is calculated in a two-dimensional system at a GaAs/Al_xGa_1−xAs heterojunction. Scattering mechanisms are assumed to be the Coulomb scattering from ionized donors in the Al_xGa_1−xAs layer, interface roughness, and scattering caused by alloy disorder present in the Al_xGa_1−xAs layer. The calculated mobility for the Coulomb scattering explains recent experimental results. The interface roughness and the alloy scattering can play a role at high electron concentrations (∼10¹² cm⁻²).