Optimal design for micro-thermoelectric generators using finite element analysis

To fabricate micro-thermoelectric generators (@mTEGs), one must design the optimal structure of the @mTEGs and achieve thermoelectric thin films with excellent properties. This study investigated the role of the dimensions of @mTEGs, including the length of the thermoelements, thickness of the substrates, and cross-sectional area of the thermoelements. To evaluate the power generated by @mTEGs and their efficiency, three-dimensional models of @mTEGs were subjected to finite element analysis. Three-dimensional models are more accurate than one-dimensional models, since the directions of the heat flux and electrical current are not parallel in @mTEGs. The governing equations were derived from the Seebeck effect and Peltier effect, which show thermoelectric energy conversion. In the simulation, the substrate, n-type material, and p-type material were assumed to be silicon, Bi"2Te"3, and Sb"2Te"3, respectively. We calculated the thermoelectric power generated by the @mTEGs and their thermoelectric energy conversion efficiency. These two evaluation indices represent the performance of @mTEGs. The thermoelectric simulation produced design guidelines for high-performance @mTEGs.