Thermoelectric properties of SiC thin films

Silicon carbide is expected to be a hard thermoelectric material which can be used at high temperature. Recently, a low dimensional structure has been fabricated as new materials such as thin films. We made thin films of SiC by the evaporation technique with several metal dopants which are silver, nickel and copper. These dopants act as p-type acceptors and could reduce the resistance of SiC and raise the performance as thermoelectric materials. In the 5 wt.% Ag doped samples, the thermoelectric power is about 10 μV/K at 500°C and the temperature dependence of the thermoelectric power is weak in all samples. The thermoelectric power is smaller than that of the bulk samples with the same dopants for SiC/Cu and SiC/Ag, and larger for SiC/Ni. The electrical conductivity increases as temperature increases. SiC/Ag thin films have large conductivity compared with the bulk samples. In the SiC/Ni films, the conductivity is also enhanced and the thermoelectric properties are improved at high temperature