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Title: From kinetic to collective behavior in thermal transport on semiconductors and semiconductor nanostructures

We present a model which deepens into the role that normal scattering has on the thermal conductivity in semiconductor bulk, micro, and nanoscale samples. Thermal conductivity as a function of the temperature undergoes a smooth transition from a kinetic to a collective regime that depends on the importance of normal scattering events. We demonstrate that in this transition, the key point to fit experimental data is changing the way to perform the average on the scattering rates. We apply the model to bulk Si with different isotopic compositions obtaining an accurate fit. Then we calculate the thermal conductivity of Si thin films and nanowires by only introducing the effective size as additional parameter. The model provides a better prediction of the thermal conductivity behavior valid for all temperatures and sizes above 30 nm with a single expression. Avoiding the introduction of confinement or quantum effects, the model permits to establish the limit of classical theories in the study of the thermal conductivity in nanoscopic systems.
Authors:
; ;  [1] ;  [2]
  1. Department of Physics, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia (Spain)
  2. Materials Science Institute, University of Valencia, P. O. Box 22085, 46071 Valencia (Spain)
Publication Date:
OSTI Identifier:
22273496
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ISOTOPE RATIO; QUANTUM WIRES; SCATTERING; SEMICONDUCTOR MATERIALS; TEMPERATURE DEPENDENCE; THERMAL CONDUCTIVITY; THIN FILMS