Hossain, M. Z. and Johnson, H. T. (2012) Electron-dependent thermoelectric properties in Si/Si_(1_x)Ge_(x) heterostructures and Si_(1-x)Ge_(x) alloys from first-principles. Applied Physics Letters, 100 (25). Art. No. 253901. ISSN 0003-6951. doi:10.1063/1.4729765. https://resolver.caltech.edu/CaltechAUTHORS:20120725-112555546
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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.
Item Type: | Article | |||||||||
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Additional Information: | © 2012 American Institute of Physics. Received 9 April 2012; accepted 1 June 2012; published online 18 June 2012. | |||||||||
Subject Keywords: | ab initio calculations; Ge-Si alloys; Seebeck effect; thermal conductivity; thermoelectric power | |||||||||
Issue or Number: | 25 | |||||||||
Classification Code: | PACS: 72.20.Pa; 66.70.Df | |||||||||
DOI: | 10.1063/1.4729765 | |||||||||
Record Number: | CaltechAUTHORS:20120725-112555546 | |||||||||
Persistent URL: | https://resolver.caltech.edu/CaltechAUTHORS:20120725-112555546 | |||||||||
Official Citation: | Electron-dependent thermoelectric properties in Si/Si[sub 1-x]Ge[sub x] heterostructures and Si[sub 1-x]Ge[sub x] alloys from first-principles M. Z. Hossain and H. T. Johnson, Appl. Phys. Lett. 100, 253901 (2012), DOI:10.1063/1.4729765 | |||||||||
Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. | |||||||||
ID Code: | 32713 | |||||||||
Collection: | CaltechAUTHORS | |||||||||
Deposited By: | Aucoeur Ngo | |||||||||
Deposited On: | 25 Jul 2012 20:06 | |||||||||
Last Modified: | 09 Nov 2021 21:29 |
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