Tuesday, August 23, 2016

Aalto University Finland produces large-area thermoelectric nanostructures by ALD

Here is an interesting ALD energy application by Aalto University researchers published in Nanotechweb and in Nanotechnology (abstract below): Nanotechnology offers a potential route towards improved thermoelectric conversion efficiency. Atomic layer deposition (ALD) has also recently become increasingly interesting for thermoelectrics as it allows bottom-up fabrication of complex nanostructures in a parallel fashion. The research on large-area thermoelectric nanostructures carried out at Aalto University and reported in Nanotechnology, paves the way for novel fabrication approaches for energy conversion devices.




Continue reading: http://nanotechweb.org/cws/article/lab/65989 

Large-area thermoelectric high-aspect-ratio nanostructures by atomic layer deposition 

Mikko Ruoho, Taneli Juntunen and Ilkka Tittonen

Published 25 July 2016 • © 2016 IOP Publishing Ltd
Nanotechnology, Volume 27, Number 35

Abstract :
We report on the thermoelectric properties of large-area high-aspect-ratio nanostructures. We fabricate the structures by atomic layer deposition of conformal ZnO thin films on track-etched polycarbonate substrate. The resulting structure consists of ZnO tubules which continue through the full thickness of the substrate. The electrical and thermal properties of the structures are studied both in-plane and out-of-plane. They exhibit very low out-of-plane thermal conductivity down to 0.15 W m−1 K−1 while the in-plane sheet resistance of the films was found to be half that of the same film on glass substrate, allowing material-independent doubling of output power of any planar thin-film thermoelectric generator. The wall thickness of the fabricated nanotubes was varied within a range of up to 100 nm. The samples show polycrystalline nature with (002) preferred crystal orientation.