Reliability and Diffusion Study at the Interface Between Thermoelectric Semiconductors and Electrode Metals with Barrier Materials.

In a world where energy is ever more important studies have been focusing on renewable technology for energy generation, many of which have encountered roadblocks that prevented their widespread adoption. Thus, it is of great interest to look to new technologies whose potential is still relatively untapped, such as ThermoElectric Generation (TEG) devices, able to generate energy by using the Seebeck effect. The basic configuration includes semiconductor chips bonded to an electrode through solder (such as AgSn solder). But due to an exceedingly low melting point, the operational temperature range is not wide enough so in this work a Ag/Epoxy based paste will be evaluated as a substitute. The main evaluated characteristic will be the mechanical strength and its evolution with time through a thermal aging experiment. At the same time, the cross-section will be examined to gain more information on the aging mechanism. Finally, elemental diffusion on the chip/paste interface will be modeled so to perform the first step towards accurate and reliable forecasts of the device’s properties throughout its lifetime, which would tremendously aid in the sizing and economic analysis of whomever would be interested in applying the technology.