Improved vertical silicon nanowire based thermoelectric power generator with polyimide filling

This letter demonstrates two-orders-of-magnitude enhancement in the performance of recently reported vertical silicon nanowire (SiNW)-based thermoelectric power generators (TEGs) by optimizing the filling material. As compared to SiO ₂ in the earlier work, the new device uses polyimide as filling material, which provides low parasitic thermal conduction and also reduces the damage to the nanowire tips. Consequently, an open-circuit voltage of 27.9 mV, a short-circuit current of 67 μA (both improved by ∼17×), and a maximum power output of 0.47 μW; (improved by ∼313×) were obtained under a temperature difference of 70 K across the experimental setup. The reported improvements bring SiNW-TEGs a step closer to be used as a miniaturized clean energy source.