Finite element analysis of 2-terminal perovskite-silicon tandem devices

This study presents a stress analysis of tandem perovskite-silicon modules. The results reveal a monotonic increase in peel stress as the encapsulant thickness decreases. Additionally, from the stress distribution, the potential for delamination in the perovskite layer is identified as a mixed-mode failure predominantly driven by peel stresses in the case of thinner encapsulants and driven by shear stresses in the case of thicker encapsulants. From the strain energy release rates, it is identified that modules with thinner encapsulant have a significantly higher strain energy release rate at the perovskite-encapsulant interface, making them more prone to delamination compared to modules with thicker encapsulant. The study also shows that a reduction in encapsulant elastic modulus and busbar thickness are critical to reduce peel stress in the perovskite layer and potential for delamination. These design optimization strategies are aimed at enhancing the structural integrity of the modules and are a platform for future prediction for experimentally observed delamination.