A setup for simultaneously measureing the thermopower and electrical conductivity of $\mu $m-thickness specimens

We report the concept and configuration of our new setup for measurement of thermopower and electrical conductivity for $\mu $m-thickness specimens, especially for thermoelectric materials. It is very difficult and tedious to accurately measure the thermopower for specimens with thickness less than $\sim $100 $\mu $m due to the limitations of smallest size $\sim $25$\mu $m of thermocouples. Such are obvious when applied to the measurement of nanowire arrays and multilayer . In order to resolve these difficulties, we developed a new setup with integration of Pt-film thermometers and electrical electrodes on two sapphire chips used to clamp specimens with thickness $>$40 \textbf{$\mu $}m and cross section 2 x 3 mm$^{2}$. Use this setup the thermopower and electric conductivity can be measured simultaneously for temperature range 20-400 K. The advantages of the setup are (1) accuracy: the real temperatures of both sides of the sample can be obtained. (2) convenience for loading samples: just assemble the sample between the two microchips and make sure of a good thermal and electrical contacts. A Bi$_{2}$Te$_{3}$ nanowire array in AAO template was tested, the thermopower $\sim $ 50$\mu $V/K was measured for diameter $\sim $ 60 nm of nanowires.