Image analysis of polycrystalline solar cells and modeling of intergranular and transgranular cracking

TL;DR

This paper introduces an image analysis method for polycrystalline solar cells and models crack propagation, revealing that transgranular cracking is more common than intergranular cracking, aligning with experimental data.

Contribution

It presents a novel image analysis technique combined with a modified cohesive zone model to simulate crack patterns in polycrystalline Silicon solar cells.

Findings

Transgranular cracking is more prevalent than intergranular cracking.

The model accurately predicts crack patterns consistent with experimental observations.

Grain boundary and bulk properties significantly influence crack propagation.

Abstract

An innovative image analysis technique is proposed to process real solar cell pictures, identify grains and grain boundaries in polycrystalline Silicon, and finally generate finite element meshes. Using a modified intrinsic cohesive zone model approach to avoid mesh dependency, nonlinear finite element simulations show how grain boundaries and Silicon bulk properties influence the crack pattern. Numerical results demonstrate a prevalence of transgranular over intergranular cracking for similar interface fracture properties of grains and grain boundaries, in general agreement with the experimental observation.