Development of a two dimensional scanning Seebeck coefficient measurement system by a micro-probe method

A Seebeck micro-probe measurement system with high spatial resolution has been developed to examine two-dimensional spatial distribution of Seebeck coefficient for thermoelectric materials at room temperature. A contact area of 10 μmϕ is realized by using a Copper probe tip fabricated by a mechanical machining process. The two-dimensional spatial distribution of the Seebeck coefficient for the Bismuth–Telluride and Zinc–Antimonide systems has been measured. The sign inversion of the Seebeck coefficient from p- to n-type is clearly detected along the crystal growth direction in the Bismuth–Telluride system. On the other hand, the anisotropic Seebeck coefficient reflecting grain distribution is conspicuously observed in the Zinc–Antimonide system.