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Title: Anisotropy of Seebeck coefficient in Si/Ge composite quantum dots

Abstract

In this report, Si{sub 5}Ge{sub 5} alloy and Si/Ge composite quantum dots (CQDs) layers were grown on Si substrates. Seebeck coefficient (S) of Si and Ge wafers, as well as these two samples, were patterned and measured from 60 to 180 °C in [110] and [010] directions. For Si, Ge, and Si{sub 5}Ge{sub 5}, the S of each is a constant in this temperature range. However, the S of the CQDs at 60–80 °C is anomalous and much higher than the others. The behavior of the voltage difference is linear to the temperature difference even as large as 50 °C, except for CQDs at 60–80 °C. This result indicates that a narrow distribution of carriers energy with a sharp change in density of state near Fermi-level and selective carrier scattering in the miniband at Si/Ge interface make the discrepancy of charge transport enhanced. The CQDs can be a good candidate for temperature sensing and thermoelectric applications due to their high S and low thermal conductivity near room temperature.

Authors:
;  [1];  [2]
  1. Department of Electrical Engineering, National Central University, Taoyuan 32001, Taiwan (China)
  2. Institute of Materials Science and Engineering, National Central University, Taoyuan 32001, Taiwan (China)
Publication Date:
OSTI Identifier:
22590536
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALLOYS; ANISOTROPY; CHARGE TRANSPORT; DENSITY OF STATES; DISTRIBUTION; ELECTRIC POTENTIAL; FERMI LEVEL; INTERFACES; LAYERS; QUANTUM DOTS; SCATTERING; SUBSTRATES; TEMPERATURE RANGE 0273-0400 K; THERMAL CONDUCTIVITY

Citation Formats

Hsin, Cheng-Lun, E-mail: clhsin@ee.ncu.edu.tw, Tsai, Yue-Yun, and Lee, Sheng-Wei. Anisotropy of Seebeck coefficient in Si/Ge composite quantum dots. United States: N. p., 2016. Web. doi:10.1063/1.4961535.
Hsin, Cheng-Lun, E-mail: clhsin@ee.ncu.edu.tw, Tsai, Yue-Yun, & Lee, Sheng-Wei. Anisotropy of Seebeck coefficient in Si/Ge composite quantum dots. United States. doi:10.1063/1.4961535.
Hsin, Cheng-Lun, E-mail: clhsin@ee.ncu.edu.tw, Tsai, Yue-Yun, and Lee, Sheng-Wei. Mon . "Anisotropy of Seebeck coefficient in Si/Ge composite quantum dots". United States. doi:10.1063/1.4961535.
@article{osti_22590536,
title = {Anisotropy of Seebeck coefficient in Si/Ge composite quantum dots},
author = {Hsin, Cheng-Lun, E-mail: clhsin@ee.ncu.edu.tw and Tsai, Yue-Yun and Lee, Sheng-Wei},
abstractNote = {In this report, Si{sub 5}Ge{sub 5} alloy and Si/Ge composite quantum dots (CQDs) layers were grown on Si substrates. Seebeck coefficient (S) of Si and Ge wafers, as well as these two samples, were patterned and measured from 60 to 180 °C in [110] and [010] directions. For Si, Ge, and Si{sub 5}Ge{sub 5}, the S of each is a constant in this temperature range. However, the S of the CQDs at 60–80 °C is anomalous and much higher than the others. The behavior of the voltage difference is linear to the temperature difference even as large as 50 °C, except for CQDs at 60–80 °C. This result indicates that a narrow distribution of carriers energy with a sharp change in density of state near Fermi-level and selective carrier scattering in the miniband at Si/Ge interface make the discrepancy of charge transport enhanced. The CQDs can be a good candidate for temperature sensing and thermoelectric applications due to their high S and low thermal conductivity near room temperature.},
doi = {10.1063/1.4961535},
journal = {Applied Physics Letters},
number = 8,
volume = 109,
place = {United States},
year = {Mon Aug 22 00:00:00 EDT 2016},
month = {Mon Aug 22 00:00:00 EDT 2016}
}