Electron mobility in compensated GaAs and AlxGa1−xAs

Abstract

A term μ_CA in electron mobility proportional to T^−1/2 is observed in highly compensated GaAs and Al_xGa_1−xAs. μ_CA has previously been thought to be due to space‐charge scattering. Illumination with above‐band‐gap light is found to have no effect on μ_CA. Thus it could not be due to scattering from space‐charge regions, which are collapsed by such illumination. μ_CA is found to be proportional to N⁻¹_A in nonintentionally doped specimens where C is the major shallow acceptor. For intentional compensation with Ge and Zn, no decrease in μ_CA is observed. μ_CA may be due to scattering from the local central‐cell potential of the strongly electronegative C.