Semiconducting polymer contributes favorably to the Seebeck coefficient in multi-component, high-performance n-type thermoelectric nanocomposites

摘要

n-Type semiconducting polymers bearing high Seebeck coefficients (S) have been seldom employed in organic-inorganic thermoelectric nanocomposites (TENCs). Herein we illustrate how to exploit an n-type semiconducting polymer to fabricate TENCs comprising N2200 and metallic Co NWs, in which N2200 contributes significantly to the S of the TENCs. The TENCs exhibit a highest power factor (PF) of 288 mu W m(-1) K-2 at 80 wt% Co NWs. At a greater Co NW content, the organic/inorganic inter-connectivity deteriorates, owing to the rigid molecular chains of N2200, retarding the increase of electrical conductivity (sigma) and also undermining the mechanical flexibility. Flexible n-type doped SWCNTs were therefore added to introduce additional conductive paths. At an optimal amount of SWCNTs (2 wt%), the sigma increases to 1860 S cm(-1), whereas S remains at approximately -45 mu V K-1 and the bendability is improved. The maximal PF and zT values of the resulting ternary TENC reach 483 mu W m(-1) K-2 and 0.18 at 380 K, respectively. By pairing with p-type PEDOT:PSS/SWCNT thin films, the 6-legged flexible TEG yields maximum output voltage and power of 9.80 mV and 3.72 mu W, respectively, when Delta T = 50 K. This work manifests a new avenue to both highly efficient and bendable thermoelectric materials through the judicious choice of multiple blend components.