Large increase of the thermoelectric power factor in multi-barrier nanodevices
Antonella Masci, Elisabetta Dimaggio, Neophytos Neophytou, Dario Narducci, Giovanni Pennelli
Abstract
Improving the power factor (PF) of thermoelectric materials, crucial for enhancing the power output of thermoelectric generators, is challenging due to the adverse interdependence of the Seebeck coefficient and the electrical conductivity on carrier density. We introduce a novel strategy employing energy filtering via built-in potential barriers to alleviate this dependency, significantly enhancing the PF. Utilizing electron-beam lithography, we developed a Si-based nanodevice featuring a multiple well/barrier design. Measurements yielded a PF of 11 mW m −1 K −2 , more than doubling the optimal PF achievable in bulk silicon. Experimental findings align well with theoretical models, affirming the efficacy of the approach. Leveraging established silicon technologies in device fabrication unveils pathways for on-chip micro-energy harvesters and localized Peltier coolers. Moreover, the results validate a material-agnostic energy filtering model, guiding the creation of PF-enhanced devices across various thermoelectric materials. • New energy filtering concept on silicon experimentally doubles its thermoelectric power factor. • The design can advance energy harvesting and cooling for on-chip applications in silicon. • Multi-chip systems for autonomous, battery-free, power supply for electronics are enabled. • Theoretically, this design could boost power factors to over 5 times the pristine material optimal.