Abstract
Measurements of transport properties are reported on n-type GaAs with carrier concentrations of ∼1014 cm−3 and ∼1015 cm−3 and on p-type GaAs with carrier concentration of ∼1016 cm−3 converted from n-GaAs by heat treatments. The Hall coefficient and the resistivity have been measured as functions of temperature from 53°K to 400°K for n- and p-type samples and the resistivity has been measured as a function of hydrostatic pressure up to 15Kbar for n-type samples. The variations in the carrier concentration are explained by the presence of non-shallow donors of ionization energy ∼(0.2+1.05×10−5P(bar))eV and ∼(0.14+1.2×10−5P(bar))eV in n-GaAs, and that of non-shallow acceptors having ionization energy of 0.12 eV in p-GaAs, For n-GaAs, scatterings due to polar mode, ionized impurities and “space charge” regions produced by inhomogeneities play important roles in determining the mobility. For p-GaAs, polar optical mode scattering is the most dominant scattering mechanism and deformation potential and ionized impurity scatterings are possibly effective.
