• Yong, S.
• Sethi, Vikesh
• Nandhakumar, Iris
• Huang, R.
• Beeby, Steve
• Newbrook, Daniel W.
• Amin, A.

Abstract

<jats:title>Abstract</jats:title><jats:p>We herein report the results of a facile two-step surfactant assisted reflux synthesis of bismuth telluride (Bi<jats:sub>2</jats:sub>Te<jats:sub>3</jats:sub>) nanowires (NWs). The as-synthesised NWs had diameters ranging from 70 to 110 nm with a length varying between 0.4 and 3 <jats:italic>µ</jats:italic>m and a preferential lattice orientation of (0 1 5) as determined by grazing incidence x-ray diffraction. We demonstrate for the first time that a solvent/binder paste formulation of <jats:italic>N</jats:italic>-methyl-2-pyrrolidone/polyvinylidene fluoride (PVDF) is suitable for screen-printing the Bi<jats:sub>2</jats:sub>Te<jats:sub>3</jats:sub> NWs with the potential for the fabrication of flexible thermoelectric (TE) materials. The wt% of PVDF in the composite films was varied from 10% to 20% to identify the optimal composition with a view to achieving maximum film flexibility whilst retaining the best TE performance. The films were screen-printed onto Kapton substrates and subjected to a post-printing annealing process to improve TE performance. The annealed and screen printed Bi<jats:sub>2</jats:sub>Te<jats:sub>3</jats:sub>/PVDF NW composites yielded a maximum Seebeck coefficient −192 <jats:italic>µ</jats:italic>V K<jats:sup>−1</jats:sup> with a power factor of 34 <jats:italic>µ</jats:italic>W m<jats:sup>−1</jats:sup>K<jats:sup>−2</jats:sup> at 225 K. The flexible screen printed composite films were flexible and found to be intact even after 2000 bending cycles.</jats:p>

Topics

• impedance spectroscopy
• x-ray diffraction
• composite
• annealing
• surfactant
• Bismuth