A review of critical properties of encapsulation and edge seal materials for suitability in packaging perovskite solar cell

Perovskite solar cell (PSC) is an evolving technology with great potential to drive the solar photovoltaic industry forward, but instability arising from ingress of environmental stressors has limited the technology uptake making imminent commercialisation unattractive. This study reviews the barrier, thermal, mechanical, optical and chemical properties of several encapsulation and edge seal materials and polymer composites to advise on their suitability in packaging PSC. It proposes nanofiller composite with enhanced barriers and thermal properties for effective packaging of PSC. Implementing a systematic review process achieved by deploying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) algorithm, 11 encapsulation, 7 edge seal and 13 filler materials sourced from 110 relevant peer reviewed papers are reviewed. Graphical plot and Venn Diagram techniques are used to analyse the materials properties. The review reveals that UV cured epoxy demonstrates the potential of being the most suitable material but its relatively high-water vapour transmission rate (WVTR) of 0.16 gm -2 day -1 and low thermal conductivity of circa 0.25 W/mK limit its application. It is found that addition of boron nitride nano platelets (BNNP) to matrix of epoxy reduces the WVTR by 50%, increases the thermal conductivity significantly and is indifferent to the electrical conductivity, but addition of graphene reduces the WVTR of epoxy by 80%, increases both the thermal conductivity and electrical conductivity. Optimal weight percent of BNNP in epoxy matrix has produced composite which demonstrates suitability in packaging PSC, effectively. This review provides an insight which guides researchers on development of suitable nano-composite materials toward packaging of PSC.