A high power factor must be achieved to improve the thermoelectric (TE) output of organic TE materials though the tradeoff between electrical conductivity and the Seebeck coefficient is a serious obstacle to the further development of these materials. Here, systematic control of the electrostatic interaction between a conducting polymer and a dopant induces a positive deviation from this TE tradeoff relation so that the electrical conductivity and the Seebeck coefficient simultaneously increase. Upon reduction of the electrostatic interaction, substantial changes in the film morphology, chain conformation, and crystalline ordering are observed, all of which critically affect the TE charge transport. As a result, the electrostatic interaction control is found to be an effective strategy to enhance the power factor, overcoming the tradeoff between TE parameters. Adapting this strategy to poly(3,4‐ethylenedioxythiophene):polystyrene‐sulfonate results in a remarkable power factor (=700.2 µW m−1 K−2 ) and figure of merit ZT (=0.25).

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A surficial molecular dipole effect depending on ion‐molecular interactions has been crucial issues regarding to an interfacial potential, which can modulate solid electronic and electrochemical systems. Their properties near the interfacial region can be dictated by specific interactions between surface and adsorbates, but understandings of the corresponding details remain at interesting issues. Here, intuitive observations of an ionic pair formation‐induced interfacial potential shifts are presented with an ionovoltaic system, and corresponding output signal variations are analyzed in terms of the surficial dipole changes on self‐assembled monolayer. With aiding of photoelectron spectroscopies and density function theory simulation, the ionic pair formation‐induced potential shifts are revealed to strongly rely on a paired molecular structure and a binding affinity of the paired ionic moieties. Chemical contributions to the binding event are interrogated in terms of polarizability in each ionic group and consistent with chaotropic/kosmotropic character of the ionic groups. Based on these findings, the ionovoltaic output changes are theoretically correlated with an adsorption isotherm reflecting the molecular dipole effect, thereby demonstrating as an efficient interfacial molecular probing method under electrolyte interfacing conditions.

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/adma.202207320.