Flexible Encapsulation with Backsheets and Frontsheets for PV Applications
Schinagl, C., Plessing, A.K., E. Url, A. Nigg, H. Muckenhuber, W. Krumlacher · EU PVSEC · 2012
Solar cells require effective protection against environmental influences so that they can convert sunlight into energy for a long time. Backsheets provide long-term protection for solar cells against mechanical and chemical influences and the effects of the weather at the backside of the solar cells. State of the art at the frontside is the usage of glass to ensure protection particularly against water vapour. For thin film PV technologies, flexibility is a major advantage compared to crystalline solar-cells. As a result new frontsheet materials, which are flexible, are in the focus. But not only flexibility is a very important property, also WVTR (water vapour transmission rate), transparency, YI (yellowing index) as well as costs have to be kept in mind. For CIGS photovoltaic devices, barrier materials with WVTR of at least 10-4 g/m2d are necessary to provide lifetime of more than 20 years. Aim of the presented work is to introduce new transparent barrier frontsheets for PV applications.