Thermoelectric Power Generation Using Large Area pn - Junctions

A new approach to thermoelectric power generation using large area pn-junctions is presented [1]. Thermally generated electron-hole pairs are separated by the built-in potential gradient of the pn-junction. A temperature gradient applied along this pn-junction causes a flux of both carrier types from the hot to the cold region. This principle allows us to use layer structures similar to solar cells as thermoelectric elements. Thermoelectric modules can be manufactured by stacking these elements. Effective development and optimization of thermoelectric elements and modules depend on a strong simulation environment based on accurate models. We use the device and circuit simulator Minimos-NT of the Institute for Microelectronics / TU Vienna for both twoand three-dimensional simulations of thermoelectric devices. Its open description language and sophisticated model server enables us to easily implement models for new materials as well as for extended temperature ranges. The models are calibrated with measured data and results from full band Monte-Carlo simulations. Experimental results for Silicon based thermoelectric elements and modules are presented and compared to simulation results.