Thermoelectric materials: problems and perspectives

Thermoelectric (TE) properties of material enable energy conversion on a pure, non pollutant way. Therefore, searching for the working materials of thermoelectric devices, so called thermoelectric materials, is an attractive area of applied, but also of fundamental physics of condensed matter. We are presenting our investigations on various physical systems which have some characteristics of a good TE material. Through these examples we show difficulties in finding or creating a TE material with high figure of merit. The difficulties are not primarily in the sample preparation, but, before all, have their origin in the nature of the physical laws.