Effects of Bending and Stretching on Hybrid Organic- Inorganic Trihalide Perovskite Solar Cells

Abstract

In the recent decade, hybrid organic- inorganic trihalide perovskite solar cells have attracted significant interest from the scientific community due to their unique optoelectrical properties, ease and low cost of fabrication. Extensive research has been carried out to understand the electrical and optical properties of this novel material with a view to boosting the efficiency of the system. However, not much has been done to understand the mechanical properties of the system. The potential brittleness which predisposes the system to crack has not been addressed. In addition, issues with regards to the response of the cell to stretching and bending have not been investigated. In this research work, lead-based and tin-based perovskite solar cells were modeled and subjected to bending and stretching forces using ABAQUSTM finite element analysis software. Preliminary analysis showed that PET is a more suitable substrate for bending applications while PDMS is more compliant for stretching purposes. Contour plots obtained showed that the relatively high modulus of elasticity and layer thickness of TiO2 nanocrystals reduces the mechanical performance of the solar cells where flexibility is desirable. High stress levels were observed on the aluminium contact layer of the structures; this is due to the huge difference in elasticity between aluminium and the organic and organic-inorganic materials. Although some immediate conclusion can be made from the results presented, implications of some of the results obtained are still unclear. It is therefore recommended that experimental work be undertaken to verify the result obtained from the simulations done. Further investigation and experimentation into cracks and failure mechanisms not covered in this research is strongly recommended in future work.