Work

Gelatin-assisted electrodeposition of ultra-thick antimony telluride films with enhanced structural density and thermoelectric performance

Year: 2026

Type: article

Abstract: The development of high-performance thermoelectric ( TE ) thick films is pivotal for the advancement of micro-thermoelectric generators ( μTEGs ), where achieving sufficient film thickness is essential to maintain a robust temperature gradient and maximize power output. However, synthesizing dense, ultra-thick Sb 2 Te 3 films via electrodeposition remains a significant challenge due to the disparate reduction kinetics of Sb and Te , which often result in porous, disordered columnar structures. In this work, we propose a gelatin-assisted electrochemical deposition strategy to regulate the growth kinetics and optimize the TE properties of p-type Sb 2 Te 3 thick films. Gelatin, acting as an interfacial leveling agent, significantly refines the nucleation process and suppresses erratic grain growth, as confirmed by systematic cross-sectional SEM and XRD analyses. The results demonstrate a radical microstructural transformation from a loose granular architecture to a highly compacted, uniform matrix. This microstructural densification, coupled with potential energy-filtering effects at the organic-inorganic interfaces, leads to a simultaneous enhancement of electrical conductivity and the Seebeck coefficient. The film optimized with 15 mg of gelatin achieved a high Seebeck coefficient of 153 μV . K -1 and an electrical conductivity of 570 S . cm -1 , while maintaining a low thermal conductivity of 0.94 W·m -1 ·K -1 , culminating in a peak ZT value of 0.47. Notably, this approach facilitates the fabrication of high-quality Sb 2 Te 3 thick films with an unprecedented thickness exceeding 650 μm . These findings establish gelatin-assisted electrodeposition as a highly scalable and potent strategy for fabricating ultra-thick films, offering a promising pathway for high-efficiency micro-scale energy harvesting and low-grade waste heat recovery applications.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2026.08.152