Moisture ingress evaluation of encapsulation materials using multiphysics modelling for perovskite solar cell packaging

Perovskite solar cell (PSC) technology is poised to drive further performance gains in photovoltaic module as well as increase in sustainability, accessibility and penetration, but packaging reliability issues have hindered its commercialisation. This investigation evaluates moisture barrier properties of five potential PSC encapsulation materials across four key climates and IEC 61215 Damp Heat Test (DHT) to advise on their encapsulation and edge seal suitability. Moisture ingress into ethylene vinyl acetate (EVA), Surlyn (Ionomer), Polyvinyl butyral (PVB), Polyisobutylene (PIB), and Polyethylene terephthalate (PET) are simulated using analytical and Finite Element Analysis (FEA) methods utilising COMSOL Multiphysics software to characterise their barrier properties. Result analysis reveals that PIB is a potential suitable encapsulation material because it possesses the lowest WVTR of about 0.01
at steady state, highest water vapour resistance of 60 g/m3 in over 30 years in tropical climate, the longest mean-time-to-failure (MTTF), and the smallest magnitude of accumulated stress rate in all the climates investigated. Ionomer demonstrates the best edge seal property – accumulating the least concentration of water vapour of 227 g/m3 magnitude in extended 5000 h of DHT. These materials are proposed for further qualifications and characterisation for suitability in packaging PSC.