Nantech Journal Club: Low thermal conductivity and improved thermoelectric performance of nanocrystalline silicon germanium films by sputtering

Paper shared by Jaime Andrés Pérez Taborda

Abstracts:

Si x Ge1−x alloys are well-known thermoelectric materials with a high figure of merit at high temperatures. In this work, metal-induced crystallization (MIC) has been used to grow Si0.8Ge0.2 films that present improved thermoelectric performance (zT = 5.6 × 10−4 at room temperature)—according to previously reported values on films—with a relatively large power factor. More importantly, a reduction in the thermal conductivity at room temperature has been found. Whereas the usual crystallization of amorphous SiGe (a-SiGe) is achieved at high temperatures and for long times, which triggers dopant loss, MIC reduces the crystallization temperature and the heating time. The associated dopant loss is thus avoided, resulting in a nanostructuration of the film. Using this method, we obtained Si0.8Ge0.2 films (grown by DC plasma sputtering) with appropriate compositional and structural properties. Different thermal treatments were tested in situ (by heating the sample inside the deposition chamber) and ex situ (annealed in an external furnace with controlled conditions). From the studies of the films by: x-ray diffraction (XRD), synchrotron radiation grazing incidence x-ray diffraction (SR-GIXRD), micro Raman, scanning electron microscopy (SEM), x-ray photoemission spectroscopy (XPS), Hall effect, Seebeck coefficient, electrical and thermal conductivity measurements, we observed that the in situ films at 500 °C presented the best zT values with no gold contamination.

Published in:

Taborda J A P, Romero J J, Abad B, Muñoz-Rojo M, Mello A, Briones F and Gonzalez M S M 2016 Low thermal conductivity and improved thermoelectric performance of nanocrystalline silicon germanium films by sputtering Nanot 27 175401
http://iopscience.iop.org/article/10.1088/0957-4484/27/17/175401/meta

Views: 114

Comment

You need to be a member of The International NanoScience Community to add comments!

Join The International NanoScience Community

Welcome - about us

Welcome! Nanopaprika was cooked up by Hungarian chemistry PhD student in 2007. The main idea was to create something more personal than the other nano networks already on the Internet. Community is open to everyone from post-doctorial researchers and professors to students everywhere.

There is only one important assumption: you have to be interested in nano!

Nanopaprika is always looking for new partners, if you have any idea, contact me at editor@nanopaprika.eu

Dr. András Paszternák, founder of Nanopaprika

Partner network:

Next partner events of TINC

We are Media Partner of:

Badge

Loading…

© 2019   Created by András Paszternák, PhD (founder).   Powered by

Badges  |  Report an Issue  |  Terms of Service