Size effects in numerical homogenization of polycrystalline silicon

Abstract

AbstractA current topic in the photovoltaic industry is the analysis and evaluation of possible structural and material properties. This requires the effective material characteristics of polycrystalline silicon, which is an important component for the functional performance of the photovoltaic modules in use. Since this assessment is associated with high costs, it is to be carried out already in the product development process. Due to very thin silicon layers, the effect of the layer thickness on the effective material characteristics has to be investigated (see ). In this work, a procedure to determine these characteristic values is listed to investigate the size effect on different film thicknesses of this material (see ). With the knowledge of the properties of the silicon single crystal with its cubic symmetry on the micro level, a homogenization of the properties to the macro level can be done. The polycrystal structure with a cubic sample geometry forms the macro level. This structure is now cut into thinning layers for investigation. The open‐source software Neper is used to create the crystal structure and the inter‐connectivity for this purpose. With the help of Matlab, this information is passed on to the finite element program Abaqus, where the results are evaluated after an elastic calculation using Python. The focus is on the expected change in material properties as a function of the layer thickness.