TFA – thermoelectric thin film – thermoelectric properties – semiconductor Bi87Sb13
Full ZT – Figure of Merit Characterization of a thermoelectric thin film / Seebeck coefficient / electric conductivity / thermal conductivity
Thermoelectric materials are used in thermoelectric generators converting a temperature gradient in a voltage. To characterize the performance of a thermoelectric material the so called figure of merit (ZT) is used.
In order to calculate the figure of merit, thermal conductivity, electric conductivity and the Seebeck coefficient have to be known.
Compared to bulk materials with the same composition, thin layers show lower thermal conductivities while electrical conductivity and Seebeck coefficient are much less affected resulting in higher ZT-values. Bismuthantimonides with various chemical composition are well known semi-conducting thermoelectric materials.
Electrical conductivity, thermal conductivity and Seebeck coefficient were measured in a temperature range of 120 K to 400 K on a Bi87Sb13 nanofilm of 142 nm thickness prepared by thermal evaporation. From these parameters ZT was calculated. ZT shows a maximum of 0.16 at room temperature (20°C).