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Mechanical properties of sintered meso-porous silicon: a numerical model.

Martini R, Depauw V, Gonzalez M, Vanstreels K, Nieuwenhuysen KV, Gordon I, Poortmans J - Nanoscale Res Lett (2012)

Bottom Line: Although the design of devices which involve this material needs an accurate evaluation of its mechanical properties, only few researchers have studied the mechanical properties of porous silicon, and no data are nowadays available on the mechanical properties of sintered porous silicon.In this work we propose a finite element model to estimate the mechanical properties of sintered meso-porous silicon.A Monte Carlo simulation has also been employed to study the effect of the actual microstructure on the mechanical properties.

View Article: PubMed Central - HTML - PubMed

Affiliation: , Department of Electrical Engineering (ESAT), KU Leuven, Kasteelpark 10, Leuven-Heverlee 3001, Belgium. Roberto.Martini@imec.be.

ABSTRACT
: Because of its optical and electrical properties, large surfaces, and compatibility with standard silicon processes, porous silicon is a very interesting material in photovoltaic and microelectromechanical systems technology. In some applications, porous silicon is annealed at high temperature and, consequently, the cylindrical pores that are generated by anodization or stain etching reorganize into randomly distributed closed sphere-like pores. Although the design of devices which involve this material needs an accurate evaluation of its mechanical properties, only few researchers have studied the mechanical properties of porous silicon, and no data are nowadays available on the mechanical properties of sintered porous silicon. In this work we propose a finite element model to estimate the mechanical properties of sintered meso-porous silicon. The model has been employed to study the dependence of the Young's modulus and the shear modulus (upper and lower bounds) on the porosity for porosities between 0% to 40%. Interpolation functions for the Young's modulus and shear modulus have been obtained, and the results show good agreement with the data reported for other porous media. A Monte Carlo simulation has also been employed to study the effect of the actual microstructure on the mechanical properties.

No MeSH data available.


Related in: MedlinePlus

PSi Young’s modulus as function of porosity. Numerical results for uniform displacements (empty squares) and uniform traction (full squares) conditions and interpolations (solid line) representing the upper and lower bounds of the homogenized Young’s modulus as function of porosity. Curves are always underneath the Voigt theoretical upper bound (dashed line).
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Figure 3: PSi Young’s modulus as function of porosity. Numerical results for uniform displacements (empty squares) and uniform traction (full squares) conditions and interpolations (solid line) representing the upper and lower bounds of the homogenized Young’s modulus as function of porosity. Curves are always underneath the Voigt theoretical upper bound (dashed line).

Mentions: Using the method presented in the previous section, the upper and the lower bounds of both the Young’s modulus and the shear modulus of 500×500×500 nm3 PSi cubes have been evaluated between 0% and 40% porosities. Evaluations of the Young’s modulus and the shear modulus obtained by this procedure and their interpolations are depicted respectively in Figures3 and4. The interpolation functions have the form A(Ψ)=ASi×(1−Ψ)k where A(Ψ) is the mechanical parameter as function of porosity Ψ, ASi is the mechanical parameter of the matrix, i.e. silicon, and k is the only fitting parameter that has to be tuned in the interpolation. This family of functions is commonly employed for the interpolation of mechanical properties of porous solids[9] and, in this work, they have been employed both for the upper bounds (UBs) and the lower bounds (LBs). The interpolating functions and the relative R2 values obtained for the Young’s modulus are as follows:


Mechanical properties of sintered meso-porous silicon: a numerical model.

Martini R, Depauw V, Gonzalez M, Vanstreels K, Nieuwenhuysen KV, Gordon I, Poortmans J - Nanoscale Res Lett (2012)

PSi Young’s modulus as function of porosity. Numerical results for uniform displacements (empty squares) and uniform traction (full squares) conditions and interpolations (solid line) representing the upper and lower bounds of the homogenized Young’s modulus as function of porosity. Curves are always underneath the Voigt theoretical upper bound (dashed line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3526399&req=5

Figure 3: PSi Young’s modulus as function of porosity. Numerical results for uniform displacements (empty squares) and uniform traction (full squares) conditions and interpolations (solid line) representing the upper and lower bounds of the homogenized Young’s modulus as function of porosity. Curves are always underneath the Voigt theoretical upper bound (dashed line).
Mentions: Using the method presented in the previous section, the upper and the lower bounds of both the Young’s modulus and the shear modulus of 500×500×500 nm3 PSi cubes have been evaluated between 0% and 40% porosities. Evaluations of the Young’s modulus and the shear modulus obtained by this procedure and their interpolations are depicted respectively in Figures3 and4. The interpolation functions have the form A(Ψ)=ASi×(1−Ψ)k where A(Ψ) is the mechanical parameter as function of porosity Ψ, ASi is the mechanical parameter of the matrix, i.e. silicon, and k is the only fitting parameter that has to be tuned in the interpolation. This family of functions is commonly employed for the interpolation of mechanical properties of porous solids[9] and, in this work, they have been employed both for the upper bounds (UBs) and the lower bounds (LBs). The interpolating functions and the relative R2 values obtained for the Young’s modulus are as follows:

Bottom Line: Although the design of devices which involve this material needs an accurate evaluation of its mechanical properties, only few researchers have studied the mechanical properties of porous silicon, and no data are nowadays available on the mechanical properties of sintered porous silicon.In this work we propose a finite element model to estimate the mechanical properties of sintered meso-porous silicon.A Monte Carlo simulation has also been employed to study the effect of the actual microstructure on the mechanical properties.

View Article: PubMed Central - HTML - PubMed

Affiliation: , Department of Electrical Engineering (ESAT), KU Leuven, Kasteelpark 10, Leuven-Heverlee 3001, Belgium. Roberto.Martini@imec.be.

ABSTRACT
: Because of its optical and electrical properties, large surfaces, and compatibility with standard silicon processes, porous silicon is a very interesting material in photovoltaic and microelectromechanical systems technology. In some applications, porous silicon is annealed at high temperature and, consequently, the cylindrical pores that are generated by anodization or stain etching reorganize into randomly distributed closed sphere-like pores. Although the design of devices which involve this material needs an accurate evaluation of its mechanical properties, only few researchers have studied the mechanical properties of porous silicon, and no data are nowadays available on the mechanical properties of sintered porous silicon. In this work we propose a finite element model to estimate the mechanical properties of sintered meso-porous silicon. The model has been employed to study the dependence of the Young's modulus and the shear modulus (upper and lower bounds) on the porosity for porosities between 0% to 40%. Interpolation functions for the Young's modulus and shear modulus have been obtained, and the results show good agreement with the data reported for other porous media. A Monte Carlo simulation has also been employed to study the effect of the actual microstructure on the mechanical properties.

No MeSH data available.


Related in: MedlinePlus