We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Electrically Programmed Doping Gradients Optimize the Thermoelectric Power Factor of a Conjugated Polymer.
- Authors
Liu, Jian; Craighero, Mariavittoria; Gupta, Vandna K.; Scheunemann, Dorothea; Paleti, Sri Harish Kumar; Järsvall, Emmy; Kim, Youngseok; Xu, Kai; Reparaz, Juan Sebastián; Koster, L. Jan Anton; Campoy‐Quiles, Mariano; Kemerink, Martijn; Martinelli, Anna; Müller, Christian
- Abstract
Functionally graded materials (FGMs) are widely explored in the context of inorganic thermoelectrics, but not yet in organic thermoelectrics. Here, the impact of doping gradients on the thermoelectric properties of a chemically doped conjugated polymer is studied. The in‐plane drift of counterions in moderate electric fields is used to create lateral doping gradients in films composed of a polythiophene with oligoether side chains, doped with 2,3,5,6‐tetrafluoro‐tetracyanoquinodimethane (F4TCNQ). Raman microscopy reveals that a bias voltage of as little as 5 V across a 50 µm wide channel is sufficient to trigger counterion drift, resulting in doping gradients. The effective electrical conductivity of the graded channel decreases with bias voltage, while an overall increase in Seebeck coefficient is observed, yielding an up to eight‐fold enhancement in power factor. Kinetic Monte Carlo simulations of graded films explain the increase in power factor in terms of a roll‐off of the Seebeck coefficient at high electrical conductivities in combination with a mobility decay due to increased Coulomb scattering at high dopant concentrations. Therefore, the FGM concept is found to be a way to improve the thermoelectric performance of not yet optimally doped organic semiconductors, which may ease the screening of new materials as well as the fabrication of devices.
- Subjects
THERMOELECTRIC power; CONJUGATED polymers; BISMUTH telluride; FUNCTIONALLY gradient materials; ELECTRIC conductivity; ORGANIC semiconductors; MONTE Carlo method; POLYTHIOPHENES
- Publication
Advanced Functional Materials, 2024, Vol 34, Issue 18, p1
- ISSN
1616-301X
- Publication type
Article
- DOI
10.1002/adfm.202312549