Enhanced Thermoelectric Properties of Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) by Binary Secondary Dopants

To simultaneously increase the electrical conductivity and Seebeck coefficient of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate ( PEDOT: PSS) was a challenge for realizing efficient organic thermoelectrics. In this study, for the first time, we report both increased electrical conductivities and Seebeck coefficients, hence, enhanced thermoelectric properties of PEDOT: PSS thin films by doped with binary secondary dopants, dimethyl sulfoxide (DMSO) and poly(ethylene oxide) (PEO). Without modifying film morphology, the molar ratios of PEDOT to PSS are tuned by PEO, resulting in increased proportions of PEDOT in the bipolaron states. Our study provides a facile route to optimizing thermoelectric properties of PEDOT: PSS thin films.