Thermoelectric effect in very thin film Pt∕Au thermocouples

The thickness dependence of the thermoelectric power of Pt films of variable thicknesses on a reference Au film has been determined for the case when the Pt film thickness, t, is not large compared to the charge-carrier mean free path. Pt film thicknesses down to 2.2nm were investigated. We find that ΔSF=SB−SF (where SB and SF are the thermopowers of the Pt bulk and film, respectively) does not vary linearly as 1∕t is the case for thin film thermocouples when the film thickness is large compared to the charge-carrier mean free path.