Density of localized states in (Pb0.78Sn0.22)0.95In0.05Te solid solutions

Abstract

The hopping conductivity and the Seebeck coefficient have been measured in Pb0.78Sn0.22Te with 5 at. % In and supplementary donor doping with Cl. The experimental data obtained are compared with similar results for supplementary acceptor doping with Tl. At temperatures of 150 K and higher, the thermoelectric power changes its sign from positive to negative on the introduction in sufficient amounts of either donors or acceptors. An analysis of the dependence of the thermoelectric power on the content of supplementary donors and acceptors yields the density of localized indium states as a function of energy. The function is essentially nonmonotonic, exhibiting both a density-of-states peak and a minimum between this peak and the conduction band.