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

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 supplement ary acceptor doping with Tl. At temperatures of 150 K and higher, the therm oelectric power changes its sign from positive to negative on the introduct ion in sufficient amounts of either donors or acceptors. An analysis of the dependence of the thermoelectric power on the content of supplementary don ors and acceptors yields the density of localized indium states as a functi on of energy. The function is essentially nonmonotonic, exhibiting both a d ensity-of-states peak and a minimum between this peak and the conduction ba nd. (C) 2001 MAIK "Nauka/Interperiodica".