Enhanced thermoelectric properties of SnSe thin films grown by pulsed laser glancing-angle deposition

Suen, C. H. et al. (2017) Enhanced thermoelectric properties of SnSe thin films grown by pulsed laser glancing-angle deposition. Journal of Materiomics, 3(4), pp. 293-298. (doi: 10.1016/j.jmat.2017.05.001)

Abstract

SnSe single crystals have been demonstrated to possess excellent thermoelectric properties. In this work, we demonstrate a grain size control method in growing nanocrystalline SnSe thin films through a glancing angle pulsed-laser deposition approach. Structural characterization reveals that the SnSe film deposited at a normal angle has a preferred orientation along a axis, while by contrast, the SnSe film deposited at an 80° glancing angle develops a nanopillar structure with the growth direction towards the incident atomic flux. The glancing angle deposition greatly reduces the grain size of the thin film due to a shadowing effect to the adatoms, resulting in significantly increased power factor for more than 100%. The maximum Seebeck coefficient and power factor are 498.5 μV/K and 18.5 μWcm-1K-2, respectively. The enhancement of thermoelectric property can be attributed to the potential barrier scattering at grain boundaries owing to the reduced grain size and increased grain boundaries in the film. Given this enhanced power factor, and considering the fact that the nanopillar structure should have much lower thermal conductivity than a plain film, the zT value of such made SnSe film could be significantly larger than the corresponding single crystal film, making it a good candidate for thin film-based thermoelectric device.

• Item Type: Articles
• Additional Information: We thank support from The Hong Kong Polytechnic University (Grant Nos. 1-ZVCG, 1eZVGH, 4eZZDC, and DD7F).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Lam, Dr Koko
• Authors: Suen, C. H., Shi, D., Su, Y., Zhang, Z., Chan, C. H., Tang, X., Li, Y., Lam, K. H., Chen, X., Huang, B.L., Zhou, X.Y., and Dai, J.-Y.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Journal of Materiomics
• Publisher: Elsevier
• ISSN: 2352-8478
• ISSN (Online): 2352-8478
• Copyright Holders: Copyright: © 2017 The Chinese Ceramic Society
• First Published: First published in Journal of Materiomics 3(4): 293-298
• Publisher Policy: Reproduced under a Creative Commons licence

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