Transport properties of the two-dimensional electron gas in wide AlP quantum wells: The effects of background charged impurity and acoustic phonon scattering

We present the theoretical results of the mobility and diffusion thermopower for the quasi-two-dimensional electron gas (Q2DEG) in a GaP/AlP/GaP quantum well (QW) for interface-roughness, remote and homogenous background charged impurity, and acoustic (AC) phonon scattering. We study the dependence of the mobility and diffusion thermopower on the temperature T, carrier density n and QW width L. The exchange and correlation effects are taken into account using different approximations for the local-field correction (LFC). It is shown that, for the values of parameters employed and wide QWs with L > 125 Å, the AC phonon scattering is dominant for T > 35 K and the effects of homogenous background charged impurity scattering (BIS) on the thermopower are remarkable. For thin QWs with L < 55 Å, the mobility and diffusion thermopower are mainly determined by interface-roughness scattering (IRS). At low density and temperatures the exchange and correlation effects considerably modify the thermopower.