Work

Enhanced Thermoelectric Properties of Skutterudite Thick Film Polyvinyl Alcohol Assisted from the Post-Deposition Annealing Effect

Year: 2021

Type: article

Abstract: Thick film has demonstrated a high Seebeck coefficient, S, for thermoelectric material but it is very challenging to obtain through cost-effective techniques. Electrodeposition is adopted to tailor the film’s thickness, t, facilitated by additive and heat treatment to boost the S . Here, we report the influence of two varied molecular weight ( M w ) of polyvinyl alcohol (PVA) as additive and the post-deposition annealing temperature on Skuterrudite (cobalt triantimonide, CoSb 3 ) thick films. The films are synthesized at room temperature via chronoamperometry from an aqueous electrolyte consisting of cobalt and antimony ions assisted with PVA (1800 and 98 000 Da). Higher M w exhibits fine grains and uniform layers with the t of ∼13 μ m in 2 h deposition time due to the greater ion diffusion coefficient, D (1.52 × 10 −5 cm 2 s −1 ). The post-deposition annealing on the CoSb 3 thick film of higher M w PVA assisted revealed significant enhancement of the S and power factor, PF by over 100% as compared to the as-deposited film. Low electrical conductivity, σ of 7.53 k Sm −1 contributes to the high S and PF (annealed at 373.15 K) of 222.75 μ VK −1 and 558.17 μ Wm −1 K −2 , respectively. This work demonstrates that post-deposition annealing has a prominent effect on thermoelectric properties.

Source: Journal of The Electrochemical Society

DOI: 10.1149/1945-7111/ac13d0