Hole mobility of GaAs, GaP, and GaAs1-xPx mixed-compound semiconductors

With the use of the substitutional virtual-crystal-approximation method, the composition dependence is semiempirically estimated for the GaAs1-xPx valence-band parameter and the hole-phonon coupling constants. Alloy scattering is also investigated with the help of dielectric band theory. Taking account of the inter-valence-band interaction, we discuss theoretical hole mobility using two different approaches: the conventional effective-relaxation-time approximation and Rodes difference approximation. Owing to decreased split-off energy, the influence of inter-valence-band interaction on the hole material parameter is strengthened with increased P content and temperature.