Refined Analysis of Low-Temperature Data of Hall-Effect Measurements on Sb-Doped n-Ge on the Basis of an Impurity-Hubbard-Band Model

Abstract

The Hall-effect measurement data on Sb-doped n-Ge reported by Fritzsche [J. Phys. Chem. Solids 6, 69 (1958)] have been analyzed considering not only the bottom Hubbard band formed from the neutral donor (D0) states but also the top Hubbard band formed from the negatively charged donor (D−) states. Taking into account the degeneracy factors for the D0 and D− states as well as the dependence of the dielectric constant on the concentration of the D0 states, simultaneous fits to the experimental data of the temperature-dependent conductivity and the Hall coefficient have been performed with assuming the hopping drift mobility expressed as μi = μ0i(Eμi/kBT)3/2exp(−Eμi/kBT) and the hopping Hall factor expressed as AHi = (kBT/IHi)exp(KHEμi/kBT), where i = 2 and 3 for the top and the bottom Hubbard band, respectively. The deduced values of Eμ3 from the fits have been proved to be well explained by the molecular-pair theory. The energy separation U between the top and the bottom Hubbard band has also been obtained through the fits with assuming U = Eμ2. It is shown that the fits have been satisfactorily performed with assuming a constant value of KH= 2/3.