Deciphering the superior thermoelectric property of post-treatment-free PEDOT:PSS/IL hybrid by X-ray and neutron scattering characterization
Source abstract
Abstract
Abstract In this work, a polymer and ionic liquid (IL) hybrid with superior thermoelectric performance is prepared via a system design of the chemical composition, molar ratio of the constituent molecules and manipulating the structure in solution and dried films. The solution-casted hybrid film, consisting of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and 1-ethyl-3-methylimidazolium tricyanomethanide (EMIM:TCM), shows the highest power factor of 175 μW m−1 K−2in the polymer hybrid prepared by a post-treatment-free method. With a set of complementary structure characterization methods, it is found that EMIM:TCM can induce the structure reorganization of PEDOT:PSS in solution from a core-shell model to a rod-like model, during which PEDOT partially separates from PSS that eases the conductive network formation. In addition, the oxidation level of PEDOT:PSS is reduced by adding EMIM:TCM. Based on which, the PEDOT:PSS/IL hybrid shows the best performance in optimizing the conductivity (1163 S cm−1) and Seebeck coefficient (38.8 μV K−1) simultaneously.
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Research context
OpenAlex topics: Advanced Thermoelectric Materials and Devices · Conducting polymers and applications · Transition Metal Oxide Nanomaterials
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References (63)
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1. Petsagkourakis, I. et al. Thermoelectric materials and applications for energy harvesting power generation. Sci. Technol. Adv. Mater. 19, 836–862 (2018).10.1080/14686996.2018.1530938 ↗
2. Zhang, Q., Sun, Y., Xu, W. & Zhu, D. Organic thermoelectric materials: emerging green energy materials converting heat to electricity directly and efficiently. Adv. Mater. 26, 6829–6851 (2014).10.1002/adma.201305371 ↗
3. Siddique, A. R. M., Mahmud, S. & Van Heyst, B. A review of the state of the science on wearable thermoelectric power generators (TEGs) and their existing challenges. Renew. Sust. Energy Rev. 73, 730–744 (2017).10.1016/j.rser.2017.01.177 ↗
4. Wang, Y. et al. Flexible thermoelectric materials and generators: challenges and innovations. Adv. Mater. 31, 1807916 (2019).10.1002/adma.201807916 ↗
5. Lee, W., Lee, S., Kim, H. & Kim, Y. Organic thermoelectric devices with PEDOT:PSS/ZnO hybrid composites. Chem. Eng. J. 415, 128935 (2021).10.1016/j.cej.2021.128935 ↗
6. Bubnova, O., Berggren, M. & Crispin, X. Tuning the thermoelectric properties of conducting polymers in an electrochemical transistor. J. Am. Chem. Soc. 134, 16456–16459 (2012).10.1021/ja305188r ↗
7. Saxena, N. et al. Morphology-function relationship of thermoelectric nanocomposite films from PEDOT:PSS with silicon nanoparticles. Adv. Electron. Mater. 3, 1700181 (2017).10.1002/aelm.201700181 ↗
8. Liu, J. et al. Thermal conductivity and elastic constants of PEDOT:PSS with high electrical conductivity. Macromolecules 48, 585–591 (2015).10.1021/ma502099t ↗
9. Bharti, M. et al. Boosting thermoelectric power factor of free-standing Poly (3, 4ethylenedioxythiophene):polystyrenesulphonate films by incorporation of bismuth antimony telluride nanostructures. J. Power Sources 435, 226758 (2019).10.1016/j.jpowsour.2019.226758 ↗
10. Zhang, B., Sun, J., Katz, H., Fang, F. & Opila, R. Promising thermoelectric properties of commercial PEDOT:PSS materials and their Bi2Te3 powder composites. ACS Appl. Mater. Interfaces 2, 3170–3178 (2010).10.1021/am100654p ↗
11. Moriarty, G. P. et al. Thermoelectric behavior of organic thin film nanocomposites. J. Polym. Sci., Part B: Polym. Phys. 51, 119–123 (2013).10.1002/polb.23186 ↗
12. Yu, C., Choi, K., Yin, L. & Grunlan, J. C. Light-weight flexible carbon nanotube based organic composites with large thermoelectric power factors. ACS nano 5, 7885–7892 (2011).10.1021/nn202868a ↗
13. El-Shamy, A. G. The role of nitrogen-carbon dots (NC) nano-particles in enhancing thermoelectric power functions of PEDOT:PSS/Te nano-composite films. Chem. Eng. J. 417, 129212 (2021).10.1016/j.cej.2021.129212 ↗
14. Yi, C. et al. Enhanced thermoelectric properties of poly (3, 4-ethylenedioxythiophene):poly (styrenesulfonate) by binary secondary dopants. ACS Appl. Mater. Interfaces 7, 8984–8989 (2015).10.1021/acsami.5b01960 ↗
15. Park, H. et al. Enhanced thermoelectric properties of PEDOT:PSS nanofilms by a chemical dedoping process. J. Mater. Chem. A 2, 6532–6539 (2014).10.1039/C3TA14960A ↗
16. Li, X. et al. Effects of cationic species in salts on the electrical conductivity of doped PEDOT:PSS films. ACS Appl. Polym. Mater. 3, 98–103 (2021).10.1021/acsapm.0c01084 ↗
17. Mazaheripour, A. et al. Tailoring the Seebeck coefficient of PEDOT: PSS by controlling ion stoichiometry in ionic liquid additives. Chem. Mater. 30, 4816–4822 (2018).10.1021/acs.chemmater.8b02114 ↗
18. Saxena, N. et al. Facile Optimization of thermoelectric properties in PEDOT:PSS thin films through acido-base and redox dedoping using readily available salts. ACS Appl. Energy Mater. 1, 336–342 (2018).10.1021/acsaem.7b00334 ↗
19. Kee, S. et al. Highly stretchable and air-stable PEDOT:PSS/ionic liquid composites for efficient organic thermoelectrics. Chem. Mater. 31, 3519–3526 (2019).10.1021/acs.chemmater.9b00819 ↗
20. Saxena, N. et al. Ionic liquids as post-treatment agents for simultaneous improvement of Seebeck coefficient and electrical conductivity in PEDOT:PSS Films. ACS Appl. Mater. Interfaces 11, 8060–8071 (2019).10.1021/acsami.8b21709 ↗
21. Badre, C., Marquant, L., Alsayed, A. M. & Hough, L. A. Highly conductive poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) films using 1-ethyl-3-methylimidazolium tetracyanoborate ionic liquid. Adv. Funct. Mater. 22, 2723–2727 (2012).10.1002/adfm.201200225 ↗
22. Yue, W. et al. A highly stretchable, transparent, and conductive polymer. Sci. Adv. 3, e1602076 (2017).10.1126/sciadv.1602076 ↗
23. Kee, S. et al. Controlling molecular ordering in aqueous conducting polymers using ionic liquids. Adv. Mater. 28, 8625–8631 (2016).10.1002/adma.201505473 ↗
24. de Izarra, A., Park, S., Lee, J., Lansac, Y. & Jang, Y. H. Ionic liquid designed for PEDOT:PSS conductivity enhancement. J. Am. Chem. Soc. 140, 5375–5384 (2018).10.1021/jacs.7b10306 ↗
25. Zheng, Y. Q. et al. Unraveling the solution-state supramolecular structures of donor-acceptor polymers and their influence on solid-state morphology and charge-transport properties. Adv. Mater. 29, 1701072 (2017).10.1002/adma.201701072 ↗
26. Deng, L., Huang, X., Lv, H., Zhang, Y. & Chen, G. Unravelling the mechanism of processing protocols induced microstructure evolution on polymer thermoelectric performance. Appl. Mater. Today 22, 100959 (2021).10.1016/j.apmt.2021.100959 ↗
27. Ju, D., Kim, D., Yook, H., Han, J. W. & Cho, K. Controlling electrostatic interaction in PEDOT:PSS to overcome thermoelectric tradeoff relation. Adv. Funct. Mater. 29, 1905590 (2019).10.1002/adfm.201905590 ↗
28. Deng, L. & Chen, G. Recent progress in tuning polymer oriented microstructures for enhanced thermoelectric performance. Nano Energy 80, 105448 (2021).10.1016/j.nanoen.2020.105448 ↗
29. Kim, N. et al. Highly conductive PEDOT:PSS nanofibrils induced by solution-processed crystallization. Adv. Mater. 26, 2268–2272 (2014).10.1002/adma.201304611 ↗
30. Luo, J. et al. Enhancement of the thermoelectric properties of PEDOT:PSS thin films by post-treatment. J. Mater. Chem. A 1, 7576–7583 (2013).10.1039/c3ta11209h ↗
31. Jeong, M. H. et al. Increasing the thermoelectric power factor of solvent-treated PEDOT:PSS thin films on PDMS by stretching. J. Mater. Chem. A 6, 15621–15629 (2018).10.1039/C8TA03606C ↗
32. Lee, S. H., Park, H., Son, W., Choi, H. H. & Kim, J. H. Novel solution-processable, dedoped semiconductors for application in thermoelectric devices. J. Mater. Chem. A 2, 13380–13387 (2014).10.1039/C4TA01839G ↗
33. Ju, H., Park, D., Kim, K. & Kim, J. Exfoliated Sn-Se-Te based nanosheets and their flexible thermoelectric composites with poly (3, 4-ethylenedioxythiophene):Poly (styrenesulfonate) fabricated by solution processing. Org. Electron. 71, 131–135 (2019).10.1016/j.orgel.2019.05.017 ↗
34. Jiang, F. et al. Use of organic solvent-assisted exfoliated MoS2 for optimizing the thermoelectric performance of flexible PEDOT:PSS thin films. J. Mater. Chem. A 4, 5265–5273 (2016).10.1039/C6TA00305B ↗
35. Deng, W., Deng, L., Li, Z., Zhang, Y. & Chen, G. Synergistically boosting thermoelectric performance of PEDOT:PSS/SWCNT composites via the ion-exchange effect and promoting SWCNT dispersion by the ionic liquid. ACS Appl. Mater. Interfaces 13, 12131–12140 (2021).10.1021/acsami.1c01059 ↗
36. Li, T. et al. Effect of solvent on the solution state of conjugated polymer P7DPF including single-chain to aggregated state structure formation, dynamic evolution, and related mechanisms. Macromolecules 53, 4264–4273 (2020).10.1021/acs.macromol.0c00579 ↗
37. Chu, B. & Hsiao, B. S. Small-angle X-ray scattering of polymers. Chem. Rev. 101, 1727–1762 (2001).10.1021/cr9900376 ↗
38. Bernadó, P., Mylonas, E., Petoukhov, M. V., Blackledge, M. & Svergun, D. I. Structural characterization of flexible proteins using small-angle X-ray scattering. J. Am. Chem. Soc. 129, 5656–5664 (2007).10.1021/ja069124n ↗
39. Takano, T., Masunaga, H., Fujiwara, A., Okuzaki, H. & Sasaki, T. PEDOT nanocrystal in highly conductive PEDOT:PSS polymer films. Macromolecules 45, 3859–3865 (2012).10.1021/ma300120g ↗
40. Wiener, C. G., Wang, C., Liu, Y., Weiss, R. & Vogt, B. D. Nanostructure evolution during relaxation from a large step strain in a supramolecular copolymer-based hydrogel: a SANS investigation. Macromolecules 50, 1672–1680 (2017).10.1021/acs.macromol.6b02680 ↗
41. Murphy, R. J. et al. Scattering studies on poly (3, 4-ethylenedioxythiophene)-polystyrenesulfonate in the presence of ionic liquids. Macromolecules 48, 8989–8997 (2015).10.1021/acs.macromol.5b02320 ↗
42. Hammouda, B. Probing nanoscale structures-the sans toolbox. J. Res. Natl. Inst. Stand. Technol. 1–717 (2008).
43. Fan, Z., Li, P., Du, D. & Ouyang, J. Significantly enhanced thermoelectric properties of PEDOT:PSS films through sequential post-treatments with common acids and bases. Adv. Energy Mater. 7, 1602116 (2017).10.1002/aenm.201602116 ↗
44. Khan, Z. U. et al. Acido-basic control of the thermoelectric properties of poly (3, 4-ethylenedioxythiophene) tosylate (PEDOT-Tos) thin films. J. Mater. Chem. C 3, 10616–10623 (2015).10.1039/C5TC01952D ↗
45. Ouyang, J., Chu, C. W., Chen, F. C., Xu, Q. & Yang, Y. High-conductivity poly (3, 4-ethylenedioxythiophene):poly (styrene sulfonate) film and its application in polymer optoelectronic devices. Adv. Funct. Mater. 15, 203–208 (2005).10.1002/adfm.200400016 ↗
46. Wang, C. et al. Enhancement of conductivity and thermoelectric property of PEDOT:PSS via acid doping and single post-treatment for flexible power generator. Adv. Sustain. Syst. 2, 1800085 (2018).10.1002/adsu.201800085 ↗
47. Lee, S. H. et al. Transparent and flexible organic semiconductor nanofilms with enhanced thermoelectric efficiency. J. Mater. Chem. A 2, 7288–7294 (2014).10.1039/C4TA00700J ↗
48. Culebras, M., Gómez, C. & Cantarero, A. Enhanced thermoelectric performance of PEDOT with different counter-ions optimized by chemical reduction. J. Mater. Chem. A 2, 10109–10115 (2014).10.1039/C4TA01012D ↗
49. Mengistie, D. A. et al. Enhanced thermoelectric performance of PEDOT:PSS flexible bulky papers by treatment with secondary dopants. ACS Appl. Mater. Interfaces 7, 94–100 (2015).10.1021/am507032e ↗
50. Li, Z. et al. Mechanically robust and flexible films of ionic liquid-modulated polymer thermoelectric composites. Adv. Funct. Mater. 31, 2104836 (2021).10.1002/adfm.202104836 ↗
51. Kim, E.-G. & Brédas, J.-L. Electronic evolution of poly (3, 4-ethylenedioxythiophene)(PEDOT): From the isolated chain to the pristine and heavily doped crystals. J. Am. Chem. Soc. 130, 16880–16889 (2008).10.1021/ja806389b ↗
52. Shi, W., Zhao, T., Xi, J., Wang, D. & Shuai, Z. Unravelling doping effects on PEDOT at the molecular level: from geometry to thermoelectric transport properties. J. Am. Chem. Soc. 137, 12929–12938 (2015).10.1021/jacs.5b06584 ↗
53. Zhang, P., Rothkirch, A., Koch, M., Roth, S. & Kraus, T. Determination of the surface facets of gold nanorods in wet-coated thin films with grazing-incidence wide angle X-ray scattering. Part Part Syst. Char 36, 1900323 (2019).10.1002/ppsc.201900323 ↗
54. Müller-Buschbaum, P. The active layer morphology of organic solar cells probed with grazing incidence scattering techniques. Adv. Mater. 26, 7692–7709 (2014).10.1002/adma.201304187 ↗
55. Huang, X., Deng, L., Liu, F., Liu, Z. & Chen, G. Aggregate structure evolution induced by annealing and subsequent solvent post-treatment for thermoelectric property enhancement of PEDOT:PSS films. Chem. Eng. J. 417, 129230 (2021).10.1016/j.cej.2021.129230 ↗
56. Palumbiny, C. M. et al. The crystallization of PEDOT:PSS polymeric electrodes probed in situ during printing. Adv. Mater. 27, 3391–3397 (2015).10.1002/adma.201500315 ↗
57. Kim, N. et al. Role of interchain coupling in the metallic state of conducting polymers. Phys. Rev. Lett. 109, 106405 (2012).10.1103/PhysRevLett.109.106405 ↗
58. Bießmann, L. et al. Highly conducting, transparent PEDOT:PSS polymer electrodes from post-treatment with weak and strong acids. Adv. Electron. Mater. 5, 1800654 (2019).10.1002/aelm.201800654 ↗
59. Lu, Y. et al. The critical role of dopant cations in electrical conductivity and thermoelectric performance of n-doped polymers. J. Am. Chem. Soc. 142, 15340–15348 (2020).10.1021/jacs.0c05699 ↗
60. Kim, H. G. et al. Synthetic tailoring of solid-state order in diketopyrrolopyrrole-based copolymers via intramolecular noncovalent interactions. Chem. Mater. 27, 829–838 (2015).10.1021/cm503864u ↗
61. Lu, Y. et al. Rigid coplanar polymers for stable n-type polymer thermoelectrics. Angew. Chem. 131, 11512–11516 (2019).10.1002/ange.201905835 ↗
62. Wood, K. et al. QUOKKA, the pinhole small-angle neutron scattering instrument at the OPAL Research Reactor, Australia: design, performance, operation and scientific highlights. J. Appl. Crystallogr. 51, 294–314 (2018).10.1107/S1600576718002534 ↗
63. Zhang, P. et al. Preparation of long-range ordered nanostructures in semicrystalline diblock copolymer thin films using micromolding. Chin. J. Polym. Sci. 32, 1188–1198 (2014).10.1007/s10118-014-1506-x ↗