Synergistic effect between ordered Bi2Te2.7Se0.3 pillar array and layered Ag electrode for remarkably enhancing thermoelectric device performance

In this study, it was found that a remarkably enhanced performance could be achieved in pillar array device with layered electrode through coordinate regulation between thermoelectric pillar array and layered electrode structures. The highly ordered vertical n-Bi2Te2.7Se0.3 pillar array and layered structure Ag films were fabricated by a magnetron sputtering method. The measurement result showed that the Bi2Te2.7Se0.3 pillar array and the layered Ag film were beneficial for improvement of in-plane properties, being a promising choice for planar micro-devices. These films have been integrated into low-dimension planar devices using mask-assisted deposition technology. The performance of the pillar array device with layered Ag film electrode has been tested, which was very superior to that of the pillar array device with ordinary structure electrode. For the typical 38 legs device with layered structure electrode, the output voltage and maximum power were up to 12.4 mV and 16.02 μW, respectively, for a temperature difference of 65 K. The device could produce a 11.1 K maximum temperature difference at current of 50 mA. Our results demonstrated a route to tailor unique thermoelectric pillar array and layered electrode nanostructure inside micro-devices so as to effectively improve device performance.