Galvanomagnetic Properties of n-Type InSb at Low Temperatures. III. Transport in the Band Tailing and Hopping between Donors in the Magnetic Freeze-Out Regime

Abstract

The temperature dependence of the Hall coefficient and transeverse magnetoconductivity of n-InSb containing 2–5×10¹⁴ cm⁻³ donors has been systematically investigated in the magnetic freeze-out regime. Anomalous behavior in the low temperature conduction band transport separated from the impurity conduction is presented. Evidence is observed for the existence of mobility edge in the conduction band tail states. At high temperatures transport is predominated there by trap-limited mobility, while at lower temperatures by hopping between localized states. Hall mobility at the mobility edge well agrees with Friedman’s theory.
As for dependence of the impurity conduction on the temperature, magnetic field and donor concentration, a good agreement has been obtained between our experimental result and a recent theoretical prediction on the hopping conduction.