Organic Thermoelectric Nanocomposites Assembled via Spraying Layer-by-Layer Method

Seojin Kim; You Young Byun; InYoung Lee; Woohyeon Cho; Gyungho Kim; Mario Culebras; Junho Jang; Chungyeon Cho

doi:10.3390/nano13050866

Organic Thermoelectric Nanocomposites Assembled via Spraying Layer-by-Layer Method

Nanomaterials (Basel). 2023 Feb 25;13(5):866. doi: 10.3390/nano13050866.

Authors

Seojin Kim¹, You Young Byun¹, InYoung Lee¹, Woohyeon Cho², Gyungho Kim³, Mario Culebras⁴, Junho Jang⁵, Chungyeon Cho¹

Affiliations

¹ Department of Carbon Convergence Engineering, College of Engineering, Wonkwang University, Iksan 54538, Republic of Korea.
² Core Facility for Supporting Analysis & Imaging of Biomedical Materials, Wonkwang University, Iksan 54538, Republic of Korea.
³ DMT Company, 60, Wanggungnonggong Danji-Gil, Wanggung-Myeon, Iksan 54576, Republic of Korea.
⁴ Institute of Materials Science (ICMUV), University of Valencia, 46980 Paterna, Spain.
⁵ Wearable Platform Materials Technology Center (WMC), Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.

Abstract

Thermoelectric (TE) materials have been considered as a promising energy harvesting technology for sustainably providing power to electronic devices. In particular, organic-based TE materials that consist of conducting polymers and carbon nanofillers make a large variety of applications. In this work, we develop organic TE nanocomposites via successive spraying of intrinsically conductive polymers such as polyaniline (PANi) and poly(3,4-ethylenedioxy- thiophene):poly(styrenesulfonate) (PEDOT:PSS) and carbon nanofillers, and single-walled carbon nanotubes (SWNT). It is found that the growth rate of the layer-by-layer (LbL) thin films, which comprise a PANi/SWNT-PEDOT:PSS repeating sequence, made by the spraying method is greater than that of the same ones assembled by traditional dip coating. The surface structure of multilayer thin films constructed by the spraying approach show excellent coverage of highly networked individual and bundled SWNT, which is similarly to what is observed when carbon nanotubes-based LbL assemblies are formed by classic dipping. The multilayer thin films via the spray-assisted LbL process exhibit significantly improved TE performances. A 20-bilayer PANi/SWNT-PEDOT:PSS thin film (~90 nm thick) yields an electrical conductivity of 14.3 S/cm and Seebeck coefficient of 76 μV/K. These two values translate to a power factor of 8.2 μW/m·K², which is 9 times as large as the same films fabricated by a classic immersion process. We believe that this LbL spraying method will open up many opportunities in developing multifunctional thin films for large-scaled industrial use due to rapid processing and the ease with which it is applied.

Keywords: carbon nanotubes; layer-by-layer; polymer nanocomposites; spraying; thermoelectric.

Grants and funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF-2021R1F1A1049361). This research was also financially supported by the Ministry of Small and Medium-sized Enterprises (SMEs) and Startups (MSS), Korea, under the “Regional Specialized Industry Development Plus Program (R&D, S01237)” supervised by the Korea Technology and Information Promotion Agency (TIPA). J. Jang thankfully acknowledges financial support by the Sejong Science Fellowship (NRF-2022R1C1C 2003017). Mario Culebras thanks the Grant PID2021-124845OA-I00 funded by MCIN/AEI/10.13039/501100011033 and by the “European Union NextGenerationEU/PRTR”.