Thermoelectric properties of undoped PbSe and PbTe tin alloyed epitaxial MBE-films on BaF2-substrates

We report on the thermoelectric properties for roomtemperature applications of molecular beam epitaxy grown PbSe and PbTe thin films alloyed using only a tin metal Knudsen effusion cell for tin-contents up to 10at%. Special care was taken to evaluate the in-plane thermal conductivity using a bridge method. Independent IR-thermographie verify thermal data derived from these electrical measurements. It was found that for both host IV-VI compounds increasing tin concentration results in increased charge carrier concentrations and in decreased thermopower values. As expected the lattice thermal conductivity also decreases due to alloy scattering.