Power factor measurements of bismuth telluride nanowires grown by pulsed electrodeposition
Résumé
The power factors of bismuth telluride nanowires were determined. Large-scale thermopower measurements of the nanowire arrays were performed under a constant thermal gradient. The local electrical resistance of individual nanowires inside alumina matrix was investigated at ambient conditions by a conductive tip attached to an atomic force microscope (AFM). In order to prevent oxide formation on the nanowire tips, an Au electrode segment was electrochemically deposited onto the nanowires. The optimized structural properties led to a significant improvement of the electrical conductivity of the nanowires from 0.053 to 0.169 × 106 (Ω m)-1 and their Seebeck coefficient also increased moderately from 46.6 μV/K to 55 μV/K. Based on our measurement approach, the determined maximum power factor is 476.3 μW/mK2, which is one of the highest reported values for electrodeposited Bi2Te3 nanowires.