Reduction of thermal conductivity by surface scattering of phonons in periodic silicon nanostructures

2016 ◽  
Vol 93 (4) ◽  
Author(s):  
Roman Anufriev ◽  
Jeremie Maire ◽  
Masahiro Nomura
Keyword(s):  
Thermal Conductivity ◽  
Surface Scattering ◽  
Silicon Nanostructures

Phonon surface scattering controlled length dependence of thermal conductivity of silicon nanowires

2013 ◽  
Vol 15 (35) ◽  
pp. 14647 ◽  
Author(s):  
Guofeng Xie ◽  
Yuan Guo ◽  
Baohua Li ◽  
Liwen Yang ◽  
Kaiwang Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Silicon Nanowires ◽  
Surface Scattering ◽  
Length Dependence

scholarly journals Thermal conductivity of isotopically controlled silicon nanostructures

2014 ◽  
Vol 16 (1) ◽  
pp. 015021 ◽  
Author(s):  
H Bracht ◽  
S Eon ◽  
R Frieling ◽  
A Plech ◽  
D Issenmann ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Silicon Nanostructures

The Effect of Cross-sectional Geometry on ZT Enhancement in Rough Silicon Nanostructures

2010 ◽  
Vol 1267 ◽  
Author(s):  
Jyothi Swaroop Sadhu ◽  
Marc G Ghossoub ◽  
Sanjiv Sinha
Keyword(s):  
Thermal Conductivity ◽  
Boundary Condition ◽  
Cross Section ◽  
Silicon Nanowires ◽  
Silicon Nanostructures ◽  
Dramatic Reduction ◽  
Cross Sectional ◽  
The Wire ◽  
Phonon Localization ◽  
The Impact

AbstractThe dramatic reduction in the thermal conductivity of rough silicon nanowires is due to phonon localization in the wire resulting from multiple scattering of phonons from the rough walls. We report the dependence of thermal conductivity of the nanowires as a function of the surface roughness and the diameter of the wire by modeling the nanowire as a waveguide. In addition, we estimate the impact of boundary condition, dimensionality and cross section of rough wire on the thermal conductivity. This theoretical model gives insights for tailoring thermal conductivity and enhancing the ZT of silicon to 1 for its use in thermoelectrics

Measurement of the Intrinsic Thermal Conductivity of Individual Silicon Nanoribbons

2012 ◽  
Author(s):  
Yang Yang ◽  
Deyu Li ◽  
Youfei Jiang ◽  
Zhe Guan ◽  
Terry T. Xu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Characteristic Size ◽  
Silicon Nanostructures ◽  
Si Nanowires ◽  
One Dimensional ◽  
Size Dependent ◽  
The Past ◽  
Different Diameters ◽  
Source Sink ◽  
Significant Attention

One-dimensional semiconductor nanowires, which show strong size dependent properties, have attracted significant attention during the past decade. The small characteristic size and unique physical properties can lead to broad applications such as nanoelectronics, photonics, and energy conversion. As the most widely used semiconductor material, silicon nanostructures (e.g. Si nanowires/nanoribbons) have drawn a lot of interest. Significant amount of efforts have been taken to understand their thermal properties. Experimentally, there have been a few reports on the thermal conductivity (κ) of individual 1D silicon nanostructures. Li et al. [1] first acquired the thermal conductivity of individual Si nanowires of different diameters. Later, the thermal conductivity of thin Si nanowires [2] and rough Si nanowires [3] has been measured using the same techniques. However, in these studies, the measured thermal conductivity is an effective one, which includes the effects of the contact thermal resistance between the Si nanowire and the heat source/sink. These effects will lead to some uncertainties in the experimental data.

Electronic Thermal Conductivity Effects of Nanoscale Conductors in a Gaseous Flow Environment

2011 ◽  
Vol 1347 ◽  
Author(s):  
Patrick L. Garrity ◽  
Kevin L. Stokes
Keyword(s):  
Thermal Conductivity ◽  
Surface Area ◽  
Impact Energy ◽  
Volume Ratio ◽  
Metal Films ◽  
Surface Scattering ◽  
Nanoelectromechanical Systems ◽  
Electronic Thermal Conductivity ◽  
Scattering Effects ◽  
Collision Density

ABSTRACTThe surrounding ambient introduces a gaseous boundary to many nanotechnology applications such as nanosensors, nanoelectromechanical systems and nanocoatings. Despite the large surface area to volume ratio of nanostructures, a formal study of the surface scattering effects induced by a gaseous boundary has received little attention. In this work, we consider the perturbing effects to the electron cloud or jellium of conducting nanostructures when submitted to a gaseous interface of varying interaction energies. Specifically, we incorporate the novel experimental method of Dynamic Electron Scattering (DES) to measure electronic thermal conductivity of 30 nm thick Au and Cu metal films in He and Ar atmospheres. The gas particle impact energy is varied by changing the flow speed from stationary (non-moving gas field) to high speed flow over the metal films. The scattering effects of each gas are clearly observable through electronic thermal conductivity reductions as the gas impact energy increases. We find the high collision density of He to induce greater reductions in thermal conductivity than the much heavier Ar with lower collision density. The perturbed transport properties of the Au and Cu thin films are explained by kinetic surface scattering mechanisms that dominate the scattering landscape of high surface area to volume ratio materials as suggested by comparative measurements on bulk Cu.

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