Two-dimensional electron transport in selectively doped Ga0.25In0.75As0.5P0.5/InP heterostructure

The Hall mobility of the two-dimensional electron gas in selectively doped Ga0.25In0.75As0.5P0.5, lattice matched to InP, is calculated in the temperature range from 4.2 to 300 K. The pseudo-two-mode nature of the polar optic phonons is considered in addition to deformation potential acoustic, piezoelectric, alloy, ionized impurity (remote and background), and surface roughness scattering. The energy-band nonparabolicity and screening effects on the scattering probabilities are incorporated. The Boltzmann equation is solved by an iterative method and compared with the available experimental data. It is found that at low temperature, with a suitable choice of the alloy scattering potential, theory agrees with the experiment while there are discrepancies between the theory and experimental data on mobility as the temperature increases if one considers polar scattering by the longitudinal-optical vibrations. On the other hand, theoretical results for all temperatures can be fitted with the experiment if in addition to the above scattering mechanisms, interaction with the transverse-optical phonons is assumed to take place.