A study of the impact of dislocations on the thermoelectric properties of quantum wells in the Si/SiGe materials system

Watling, J.R. and Paul, D.J. (2011) A study of the impact of dislocations on the thermoelectric properties of quantum wells in the Si/SiGe materials system. Journal of Applied Physics, 110, p. 114508. (doi:10.1063/1.3665127)

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Publisher's URL: http://dx.doi.org/10.1063/1.3665127

Abstract

Thermoelectric materials generate electricity from thermal energy using the Seebeck effect to generate a voltage and an electronic current from a temperature difference across the semiconductor. High thermoelectric efficiency ZT requires a semiconductor with high electronic conductivity and low thermal conductivity. Here, we investigate the effect of scattering from threading dislocations of edge character on the thermoelectric performance of individual n and p-channel SiGe multiple quantum well structures. Our detailed physical simulations indicate that while the thermal and electrical conductivities decrease with increasing dislocation scattering/density, the Seebeck coefficient actually increases with increasing threading dislocation density above 106 cm-2 at room temperature, due to an increase in the entropy associated with each carrier. The collective result of these individual effects, is that the present Si-based quantum well designs can tolerate scattering by a threading dislocation density up to ~108 cm-2, well within the capabilities of modern growth techniques, before significant reductions in ZT due to scattering from threading dislocations is observed.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Paul, Professor Douglas and Watling, Dr Jeremy
Authors: Watling, J.R., and Paul, D.J.
College/School:College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
Journal Name:Journal of Applied Physics
Publisher:American Institute of Physics
ISSN:0021-8979
Published Online:12 December 2011
Copyright Holders:Copyright

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