Tuning the thermoelectric properties of ZnO/MoS2/carbon fabric via interface-induced energy filtering effect for wearable thermoelectric application

• Published in: Journal of materials science. Materials in electronics 2024-05, Vol.35 (15), p.1021, Article 1021
• Main Authors: Suresh Prasanna, C., Harish, S., Eswaran, Senthil Kumar, Ikeda, H., Navaneethan, M.
• Format: Article
• Language: English
• Subjects: Activation energy; Carbon; Carrier density; Carrier mobility; Characterization and Evaluation of Materials; Chemistry and Materials Science; Decoration; Electrical resistivity; Filtration; Immersion coating; Materials Science; Molybdenum disulfide; Nanoparticles; Optical and Electronic Materials; Power factor; Power management; Power sources; Seebeck effect; Substrates; Synergistic effect; Thermoelectric generators; Thermoelectric materials; Wearable technology; Zinc oxide
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-024-12680-8

Wearable thermoelectric generators, capable of converting human body heat into electricity are one of the most suitable forms of power source to fabricate self-powered wearable electronic devices. Molybdenum disulfide (MoS 2 ), owing to its large intrinsic bandgap and high carrier mobility is one of the most widely explored materials for thermoelectric application. In this work, 2D MoS 2 nanosheets were grown on the conductive carbon fabric (CF) by a binder-free in situ hydrothermal method and the 3D ZnO nanoparticles were decorated on them via a facile dip coating technique, to form a 3D/2D interface. Apart from providing a flexible substrate to the material, the CF aids the MoS 2 with higher carrier concentration and mobility. Thus, the pristine MoS 2 possesses the highest electrical conductivity ( σ ) of all the samples at 373 K. The 20-mg ZnO-decorated sample achieved a maximum Seebeck coefficient ( S ) of 11.7 μV/K at 373 K, which is 1.25 times higher than that of pristine MoS 2 /CF. This enhancement in S is ascribed to the higher energy filtering effect at the ZnO/MoS 2 interface that allows the flow of only high-energy carriers. The 15-mg ZnO-decorated sample with optimum S and σ had the highest power factor (PF) of 311 nW/mK 2 at 373 K which is 1.2 times higher than that of the pristine sample. This enhancement in PF is mainly due to the synergistic effect of large σ and an extremely low activation energy of 0.00802 eV. Thus, the optimum concentration of ZnO nanoparticles for an enhanced PF is 15 mg owing to its very low activation energy.