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 SiO2 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 mu A (both improved by similar to 17x), and a maximum power output of 0.47 mu W (improved by similar to 313x) 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.