Development of a burst voltage measurement system for high-resolution contact resistance tests of thermoelectric heterojunctions

The recent enhanced search for high ZT thermoelectric (TE) materials has brought on new challenges to accurately characterize the contact resistance between the TE material and selected metallic bonds. Current technology for contact resistance measurements involve the sequential, physical placement of voltage probe or probes along the surface, curve-fitting the data and subsequent interpolation of voltage discontinuities at the heterojunction. An improved technology has now been developed that utilizes a burst voltage measurement system which rapid tests and re-tests voltage with very high resolution and speed. This is done by starting a burst test and linearly dragging a voltage probe across the heterojunction. The resulting voltage profile yields accuracy, speed and resolution beyond that available with the "move and reset" technology currently employed.