Effect of substrate on the spatial resolution of Seebeck coefficient measured on thermoelectric films

In this study, the effect of substrate on the spatial resolution of Potential Seebeck Microprobe apparatus, which is aimed to determine the distribution of local Seebeck coefficients on a sample surface, has been investigated for thermoelectric film measurements. The objective is to improve the spatial resolution by using the combination of ANSYS coupled-field numerical simulation and Digital Signal Processing. The results showed that the heat flow into the substrate causes a significant distortion of captured Seebeck coefficients, leading to a low resolved performance. However, we found that the characteristic of Potential Seebeck Microprobe system is similar to a low-pass filter and an equivalent width of original and captured signals can be used for predicting the Seebeck signal width. By only selecting the values of transfer function within the half power point, the correct Seebeck coefficients can be successfully predicted by the inverse method. The spatial resolution of Potential Seebeck Microprobe can be thus improved on the thermoelectric film measurements.