Nonlinear Galvanomagnetic Phenomena in Cadmium Sulfide

Abstract

A general expression for the galvanomagnetic coefficients of hot electrons in an anisotropic medium is derived on the basis of the Boltzmann transport equation. The expression is applied to a nondegenerate piezoelectric semiconductor to understand the observed anisotropy and the field dependence of the Hall mobility of cadmium sulfide. Two mechanisms, piezoelectric and deformation potential scatterings, are considered, and a distribution function is derived by solving the Boltzmann equation directly. Satisfactory agreement between theory and experiment is obtained by taking the electron effective mass 0.17 m₀ where m₀ is the bare electron mass and the deformation potential constant Ξ=16±2 eV. The anisotropic effect at low temperatures is concluded to be due to the anisotropy of piezoelectric tensors which characterizes the scattering. Effects due to other scattering mechanisms are discussed.