Compact multifunctional test structure to measure the in-plane thermoelectric figure of merit ZT of thin films

In response to recently renewed interest in thermoelectrics, this paper reports a novel compact, multifunctional test structure to measure the in-plane thermoelectric figure of merit ZT of thin films. All material parameters contributing to ZT = S²Tκ^-1ρ^-1 are determined on a single sample with dimensions of about 500×500 μm². These are the Seebeck coefficient S, the thermal conductivity κ, and the electrical resistivity ρ. The method can be applied to thin films deposited at high temperature (T), such as poly-Si, and at low T, such as metal layers. We report the temperature-dependent ZT of n-doped poly-Si from 300 to 380 K, as well as the application of the device to Al thin films.