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Title: Thermal conductivity of amorphous and nanocrystalline silicon films prepared by hot-wire chemical-vapor deposition

Abstract

We report 3..omega.. thermal conductivity measurements of amorphous and nanocrystalline silicon thin films from 85 to 300 K prepared by hot-wire chemical-vapor deposition, where the crystallinity of the films is controlled by the hydrogen dilution during growth. The thermal conductivity of the amorphous silicon film is in agreement with several previous reports of amorphous silicon prepared by a variety of deposition techniques. The thermal conductivity of the as-grown nanocrystalline silicon film is 70% higher and increases 35% more after an anneal at 600 degrees C. They all have similarly weak temperature dependence. Structural analysis shows that the as-grown nanocrystalline silicon is approximately 60% crystalline, nanograins and grain boundaries included. The nanograins, averaging 9.1 nm in diameter in the as-grown film, are embedded in an amorphous matrix. The grain size increases to 9.7 nm upon annealing, accompanied by the disappearance of the amorphous phase. We extend the models of grain boundary scattering of phonons with two different non-Debye dispersion relations to explain our result of nanocrystalline silicon, confirming the strong grain size dependence of heat transport for nanocrystalline materials. However, the similarity in thermal conductivity between amorphous and nanocrystalline silicon suggests the heat transport mechanisms in both structures may not bemore » as dissimilar as we currently understand.« less

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
US Department of the Navy, Office of Naval Research (ONR)
OSTI Identifier:
1378894
Report Number(s):
NREL/JA-5J00-69127
Journal ID: ISSN 2469-9950; PRBMDO
DOE Contract Number:
AC36-08GO28308
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 96; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; thermal conductivity; thin films

Citation Formats

Jugdersuren, B., Kearney, B. T., Queen, D. R., Metcalf, T. H., Culbertson, J. C., Chervin, C. N., Stroud, R. M., Nemeth, W., Wang, Q., and Liu, Xiao. Thermal conductivity of amorphous and nanocrystalline silicon films prepared by hot-wire chemical-vapor deposition. United States: N. p., 2017. Web. doi:10.1103/PhysRevB.96.014206.
Jugdersuren, B., Kearney, B. T., Queen, D. R., Metcalf, T. H., Culbertson, J. C., Chervin, C. N., Stroud, R. M., Nemeth, W., Wang, Q., & Liu, Xiao. Thermal conductivity of amorphous and nanocrystalline silicon films prepared by hot-wire chemical-vapor deposition. United States. doi:10.1103/PhysRevB.96.014206.
Jugdersuren, B., Kearney, B. T., Queen, D. R., Metcalf, T. H., Culbertson, J. C., Chervin, C. N., Stroud, R. M., Nemeth, W., Wang, Q., and Liu, Xiao. Sat . "Thermal conductivity of amorphous and nanocrystalline silicon films prepared by hot-wire chemical-vapor deposition". United States. doi:10.1103/PhysRevB.96.014206.
@article{osti_1378894,
title = {Thermal conductivity of amorphous and nanocrystalline silicon films prepared by hot-wire chemical-vapor deposition},
author = {Jugdersuren, B. and Kearney, B. T. and Queen, D. R. and Metcalf, T. H. and Culbertson, J. C. and Chervin, C. N. and Stroud, R. M. and Nemeth, W. and Wang, Q. and Liu, Xiao},
abstractNote = {We report 3..omega.. thermal conductivity measurements of amorphous and nanocrystalline silicon thin films from 85 to 300 K prepared by hot-wire chemical-vapor deposition, where the crystallinity of the films is controlled by the hydrogen dilution during growth. The thermal conductivity of the amorphous silicon film is in agreement with several previous reports of amorphous silicon prepared by a variety of deposition techniques. The thermal conductivity of the as-grown nanocrystalline silicon film is 70% higher and increases 35% more after an anneal at 600 degrees C. They all have similarly weak temperature dependence. Structural analysis shows that the as-grown nanocrystalline silicon is approximately 60% crystalline, nanograins and grain boundaries included. The nanograins, averaging 9.1 nm in diameter in the as-grown film, are embedded in an amorphous matrix. The grain size increases to 9.7 nm upon annealing, accompanied by the disappearance of the amorphous phase. We extend the models of grain boundary scattering of phonons with two different non-Debye dispersion relations to explain our result of nanocrystalline silicon, confirming the strong grain size dependence of heat transport for nanocrystalline materials. However, the similarity in thermal conductivity between amorphous and nanocrystalline silicon suggests the heat transport mechanisms in both structures may not be as dissimilar as we currently understand.},
doi = {10.1103/PhysRevB.96.014206},
journal = {Physical Review B},
number = 1,
volume = 96,
place = {United States},
year = {Sat Jul 01 00:00:00 EDT 2017},
month = {Sat Jul 01 00:00:00 EDT 2017}
}