Size and temperature effects on thermoelectric power of β-tin thin films

Tin thin films of thicknesses in the range 500-7000 Å have been prepared by vacuum deposition at room temperature at a pressure of 5×10-5 Torr on glass substrates. Thermal electromotive forces (emfs) of these films have been measured after aging as a function of temperature difference. It is found that the thermoelectric power of the films is independent of temperature in the range studied (300-425°K). It is also found that the thermoelectric power of the films obeys the inverse thickness dependence predicted by size effect theories. The electronic mean free path is evaluated to be 530 Å.