ethylene vinyl acetate (EVA)
Ethylene vinyl acetate (EVA) is a polymer widely used, among other purposes, as an encapsulant between the glass cover of a solar module and the glass cover of the solar cells within the module. Ethylene vinyl acetate (EVA) is hard-wearing, transparent, resistant to corrosion, and flame retardant.
Problems arise, however, from the vacuum lamination process involved in sandwiching the EVA between the two sheets of glass. The disadvantages of this technology are high weight and the gap between the glass sheets at the edges, where moisture and gas can enter the photoactive layers and cause degradation. The process can't be easily automated and takes a lot of time, energy, and material. Besides, it is not possible to produce flexible modules in this way. Therefore, the development of new encapsulation processes for thin film solar cells is necessary to reduce costs and to increase competitiveness of photovoltaics.