Thermally Enhanced n‐Type Thermoelectric Behavior in Completely Organic Graphene Oxide‐Based Thin Films Academic Article uri icon

abstract

  • © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Air-stable n-type organic thermoelectric (TE) materials with high power factor are needed to produce efficient, lightweight devices that could be self-powered by harnessing waste heat. Here, a completely organic n-type TE nanocomposite is achieved by depositing layers of double-walled carbon nanotubes (DWNT) stabilized with polyethylenimine (PEI) and graphene oxide (GO) in a layer-by-layer fashion from aqueous solutions. A 30 bilayer (BL) film (≈610 nm thick), comprised of this DWNT-PEI/GO sequence, exhibits electrical conductivity of 27.3 S cm−1 and a Seebeck coefficient of −30 µV K−1, producing a power factor of 2.5 µW m−1 K−2. Low temperature thermal reduction (150 °C for 30 min) of this composite thin film significantly improves its thermoelectric performance. An electrical conductivity of 460 S cm−1 and Seebeck coefficient of −93 µV K−1 are achieved. A 30 BL DWNT-PEI/reduced graphene oxide (rGO) film (≈480 nm thick) exhibits a power factor as large as 400 µW m−1 K−2, which is one of the highest values reported for an organic n-type material. By depositing layers containing montmorillonite clay on top, these n-type nanocomposites exhibit excellent air stability. This combination of air stability and high power factor could enable efficient thermoelectric devices on flexible substrates (e.g., clothing).

author list (cited authors)

  • Cho, C., Bittner, N., Choi, W., Hsu, J., Yu, C., & Grunlan, J. C.

citation count

  • 11

publication date

  • October 2018

publisher