Limits...
Thermal conductivity and thermal boundary resistance of nanostructures.

Termentzidis K, Parasuraman J, Da Cruz CA, Merabia S, Angelescu D, Marty F, Bourouina T, Kleber X, Chantrenne P, Basset P - Nanoscale Res Lett (2011)

Bottom Line: The influence of the interfacial roughness on the thermal conductivity of semiconductor/semiconductor superlattices was studied by equilibrium and non-equilibrium molecular dynamics and on the Kapitza resistance of superlattice's interfaces by equilibrium molecular dynamics.Physical explanations are provided for rationalizing the simulation results.PACS: 68.65.Cd, 66.70.Df, 81.16.-c, 65.80.-g, 31.12.xv.

View Article: PubMed Central - HTML - PubMed

Affiliation: INSA Lyon, CETHIL UMR5008, F-69621 Villeurbanne, France. konstantinos.termentzidis@gmail.com.

ABSTRACT
: We present a fabrication process of low-cost superlattices and simulations related with the heat dissipation on them. The influence of the interfacial roughness on the thermal conductivity of semiconductor/semiconductor superlattices was studied by equilibrium and non-equilibrium molecular dynamics and on the Kapitza resistance of superlattice's interfaces by equilibrium molecular dynamics. The non-equilibrium method was the tool used for the prediction of the Kapitza resistance for a binary semiconductor/metal system. Physical explanations are provided for rationalizing the simulation results. PACS: 68.65.Cd, 66.70.Df, 81.16.-c, 65.80.-g, 31.12.xv.

No MeSH data available.


Related in: MedlinePlus

Cross-plane and in-plane thermal conductivity functions of the height of interfaces calculated by EMD and NEMD methods.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211353&req=5

Figure 4: Cross-plane and in-plane thermal conductivity functions of the height of interfaces calculated by EMD and NEMD methods.

Mentions: In Figure 4, we gathered the results for the in-plane and cross-plane thermal conductivities obtained by the two methods. The thermal conductivity is measured here in Lennard-Jones units (LJU), which correspond in real units typically to W/mK. At the low temperatures considered (T = 0.15 LJU), the period of the superlattice is comparable to that of the PMFP. The qualitative interpretation of the results shows that the thermal contact resistance of the interface has a strong influence on the superlattice thermal conductivity. The results previously obtained by NEMD method [12], and, in particular, the existence of a minimum for the in-plane thermal conductivity are now confirmed using the EMD method. The evolution of the TC as a function of the interfacial roughness is found to be non-monotonous. When the roughness of the interfaces is smaller than the superlattice's period, the in-plane thermal conductivity first decreases with increasing roughness. It reaches a minimum value which is lower by 35-40% compared to the thermal conductivity of the superlattice with smooth interfaces. For larger roughness, the thermal conductivity increases. The initial decrease of the in-plane thermal conductivity is quite intuitive if one considers the behaviour of phonons at the interfaces, which may be described by two different models. In the acoustic mismatch model [18,19], the energy carriers are modelled as waves propagating in continuous media, and phonons at the interfaces are either transmitted or specularly reflected. For atomically smooth interfaces, it is assumed that phonons experience mainly specular scattering. The roughness enhances diffuse scattering at the interface in all space direction.


Thermal conductivity and thermal boundary resistance of nanostructures.

Termentzidis K, Parasuraman J, Da Cruz CA, Merabia S, Angelescu D, Marty F, Bourouina T, Kleber X, Chantrenne P, Basset P - Nanoscale Res Lett (2011)

Cross-plane and in-plane thermal conductivity functions of the height of interfaces calculated by EMD and NEMD methods.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211353&req=5

Figure 4: Cross-plane and in-plane thermal conductivity functions of the height of interfaces calculated by EMD and NEMD methods.
Mentions: In Figure 4, we gathered the results for the in-plane and cross-plane thermal conductivities obtained by the two methods. The thermal conductivity is measured here in Lennard-Jones units (LJU), which correspond in real units typically to W/mK. At the low temperatures considered (T = 0.15 LJU), the period of the superlattice is comparable to that of the PMFP. The qualitative interpretation of the results shows that the thermal contact resistance of the interface has a strong influence on the superlattice thermal conductivity. The results previously obtained by NEMD method [12], and, in particular, the existence of a minimum for the in-plane thermal conductivity are now confirmed using the EMD method. The evolution of the TC as a function of the interfacial roughness is found to be non-monotonous. When the roughness of the interfaces is smaller than the superlattice's period, the in-plane thermal conductivity first decreases with increasing roughness. It reaches a minimum value which is lower by 35-40% compared to the thermal conductivity of the superlattice with smooth interfaces. For larger roughness, the thermal conductivity increases. The initial decrease of the in-plane thermal conductivity is quite intuitive if one considers the behaviour of phonons at the interfaces, which may be described by two different models. In the acoustic mismatch model [18,19], the energy carriers are modelled as waves propagating in continuous media, and phonons at the interfaces are either transmitted or specularly reflected. For atomically smooth interfaces, it is assumed that phonons experience mainly specular scattering. The roughness enhances diffuse scattering at the interface in all space direction.

Bottom Line: The influence of the interfacial roughness on the thermal conductivity of semiconductor/semiconductor superlattices was studied by equilibrium and non-equilibrium molecular dynamics and on the Kapitza resistance of superlattice's interfaces by equilibrium molecular dynamics.Physical explanations are provided for rationalizing the simulation results.PACS: 68.65.Cd, 66.70.Df, 81.16.-c, 65.80.-g, 31.12.xv.

View Article: PubMed Central - HTML - PubMed

Affiliation: INSA Lyon, CETHIL UMR5008, F-69621 Villeurbanne, France. konstantinos.termentzidis@gmail.com.

ABSTRACT
: We present a fabrication process of low-cost superlattices and simulations related with the heat dissipation on them. The influence of the interfacial roughness on the thermal conductivity of semiconductor/semiconductor superlattices was studied by equilibrium and non-equilibrium molecular dynamics and on the Kapitza resistance of superlattice's interfaces by equilibrium molecular dynamics. The non-equilibrium method was the tool used for the prediction of the Kapitza resistance for a binary semiconductor/metal system. Physical explanations are provided for rationalizing the simulation results. PACS: 68.65.Cd, 66.70.Df, 81.16.-c, 65.80.-g, 31.12.xv.

No MeSH data available.


Related in: MedlinePlus