Electron-dependent thermoelectric properties in Si/Si_(1_x)Ge_(x) heterostructures and Si_(1-x)Ge_(x) alloys from first-principles
- Creators
- Hossain, M. Z.
- Johnson, H. T.
Abstract
Unlike phononic thermal conductivity (which is shown in the literature to be reduced due to alloying and has a nearly constant value over a range of compositional variations), electron-dependent thermoelectric properties are shown here, from first-principles, to vary nonlinearly with composition. Of the Si/Si_(1_x)Ge_(x) systems considered, the maximum thermopower observed, which is 10% higher than that of crystalline Si, is obtained for a Si_(0.875)Ge_(0.125) alloy. Also, heterostructuring is shown to reduce thermopower, electrical conductivity, and electron thermal conductivity. Additionally, neither Lorenz number nor Seebeck coefficient shows oscillations for heterostructures, regardless of electron/hole energies, contradicting the conclusions obtained with miniband approximations.
Additional Information
© 2012 American Institute of Physics. Received 9 April 2012; accepted 1 June 2012; published online 18 June 2012.Attached Files
Published - Hossain2012p18944Appl_Phys_Lett.pdf
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Additional details
- Eprint ID
- 32713
- Resolver ID
- CaltechAUTHORS:20120725-112555546
- Created
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2012-07-25Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field