Enhanced thermoelectric properties of germanium powder/poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) composites

• Cast poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate)/Ge composite films
• Thermoelectric properties of the composite films studied against Ge contents
• Power factor enhanced by the presence of Ge powder
• 10 times higher thermoelectric figure of merit in the Ge-containing composite films

We herein report on the enhanced thermoelectric properties of poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)/Ge composite films fabricated by drop-casting of a solution of Ge powder in PEDOT:PSS. The power factor of the fabricated PEDOT:PSS/Ge composite films with 29.6 wt.% Ge was 165 μW m− 1K− 2, and they exhibited an extremely low thermal conductivity. The maximum thermoelectric figure of merit was anticipated to be ~ 0.1 at room temperature for the PEDOT:PSS/Ge composite films with 29.6 wt.% Ge, suggesting that their heterostructure was effective in enhancing their thermoelectric efficiency.