Low temperature Hall measurements on the X1celectrons in GaAs

Abstract
Hall measurements to 120 K at 50 kbar have been carried out for electrons in the )100), X1c, satellite valleys in epitaxial and bulk grown GaAs for carrier concentrations in the range 1014-1018 cm-3. Two distinct impurity levels have been found to be associated with the X1c minima; estimates of activation energies 0.145+or-0.02 eV and 0.066+or-0.01 eV have been obtained for carrier concentrations near 1015 cm-3. The activation energies of these levels decreased with increasing carrier concentration. Theoretical analysis of mobility-temperature curves has shown intervalley scattering to be dominant for purer samples while for the heavily doped bulk grown samples space-charge scattering becomes more important. A best estimate of the (X1c-X1c) deformation potential field, Dxx, of 0.8*109 eV cm-1 for a deformation potential E1 of 5.0 eV has been obtained.