Using the Seebeck coefficient to determine charge carrier concentration, mobility, and relaxation time in InAs nanowires

Abstract

A method for determining charge carrier concentration, mobility, and relaxation time in semiconducting nanowires is presented. The method is based on measuring both the electrical conductivity and the Seebeck coefficient of the nanowire. With knowledge on the bandstructure of the material, Fermi level and charge carrier concentration can be deduced from the Seebeck coefficient. The ratio of measured conductivity and inferred charge carrier concentration then leads to the mobility, and using the Fermi level dependence of mobility one can finally obtain the relaxation time. Using this approach we exemplarily analyze the characteristics of an n-type InAs nanowire.