LAUSR

Abstract In recent years, due to very high achieved values of the thermoelectric figure of merit ZT, materials based on Cu2S are one of the most intensively studied thermoelectric materials. The problem of decomposition of these compounds under the influence of electric current, which may significantly limit the use of Cu2S based materials in practical applications, i.e. in thermoelectric generators, is very well known. This work shows that another crucial problem limiting the possibility of the practical use of Cu2S in thermoelectric devices is its low corrosion resistance to the environment containing oxygen at its operating temperature, i.e. above 400 °C, as shown by the temperature-programmed oxidation (TPOx) and the thermogravimetric (TG) measurements in air atmosphere. As a potential solution to the latter problem, amorphous layers based on Si–O–C, the so-called black glass, which protect Cu2S well against oxidation and the related degradation of the material to a temperature of approx. 600 °C, have been proposed.