Simultaneous Enhancement in Electrical Conductivity and Thermopower of n‐Type NiETT/PVDF Composite Films by Annealing |
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| Authors: | Rylan M. W. Wolfe Akanksha K. Menon Thomas R. Fletcher Seth R. Marder John R. Reynolds Shannon K. Yee |
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| Affiliation: | 1. School of Chemistry and Biochemistry, School of Materials Science and Engineering, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology, Atlanta, GA, USA;2. George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA;3. Cambridge Display Technology Ltd, Cardinal Way, Godmanchester, UK |
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| Abstract: | Nickel ethenetetrathiolate (NiETT) polymers are promising n‐type thermoelectric (TE) materials, but their insolubility requires the use of an inert polymer matrix to form films, which is detrimental to the TE performance. In this work, the use of thermal annealing as a post‐treatment process simultaneously enhances the electrical conductivity from 6 ± 2 to 23 ± 3 S cm?1 and thermopower from ?28 ± 3 to ?74 ± 4 µV K?1 for NiETT/PVDF composite films. Spectroscopic characterization reveals that the underlying mechanism involves removal of residual solvent and volatile impurities (carbonyl sulfide and water) in the NiETT polymer backbone. Additionally, microscopic characterization reveals morphological changes caused by a densification of the film that improves chain packing. These effects result in a 25 × improvement in power factor from 0.5 to 12.5 µW m?1 K?2 for NiETT/PVDF films and provide insight into the composition of these coordination polymers that maintain their stability under ambient conditions. |
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| Keywords: | composite films ethenetetrathiolates n‐type conductor organic thermoelectrics thermal annealing |
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