skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on April 1, 2017

Title: Size effects on the thermal conductivity of amorphous silicon thin films

In this study, we investigate thickness-limited size effects on the thermal conductivity of amorphous silicon thin films ranging from 3 to 1636 nm grown via sputter deposition. While exhibiting a constant value up to ~100 nm, the thermal conductivity increases with film thickness thereafter. The thickness dependence we demonstrate is ascribed to boundary scattering of long wavelength vibrations and an interplay between the energy transfer associated with propagating modes (propagons) and nonpropagating modes (diffusons). A crossover from propagon to diffuson modes is deduced to occur at a frequency of ~1.8 THz via simple analytical arguments. These results provide empirical evidence of size effects on the thermal conductivity of amorphous silicon and systematic experimental insight into the nature of vibrational thermal transport in amorphous solids.
Authors:
;  [1] ;  [1] ;  [2] ;  [2] ;  [1] ;  [2] ;  [1] ;  [1] ;  [1]
  1. Univ. of Virginia, Charlottesville, VA (United States)
  2. Univ. of New Mexico, Albuquerque, NM (United States)
Publication Date:
OSTI Identifier:
1251626
Report Number(s):
SAND--2015-6735J
Journal ID: ISSN 2469-9950; PRBMDO; 598864
Grant/Contract Number:
AC04-94AL85000
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 93; Journal Issue: 14; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE