This master thesis focuses on the characterization of the aging behavior of polymeric films for the encapsulation of photovoltaic cells and modules. Overall 6 films, also multilayer films, were investigated. As encapsulation materials ethylene vinyl acetate (EVA) and two types of ionised ethylene acrylic acid copolymer (Ionomer) were chosen. One coextruded polymethylmethycrylat (PMMA)/polyvinylidene fluoride (PVDF) multilayer was selected as glazing/backsheet material. As backsheet material a polyvinyl fluoride (PVF)/polyethylene terephthalat (PET)/PVF (TPT) and a polyethylene (PE)/PET multilayer film were investigated. Two different accelerated damp heat tests at elevated temperatures (65 and 85 °C) and humidity (85 % RH) were performed. The films were exposed for up to 5000 h. The different laminates and materials were characterised by infrared spectroscopy in attenuated total reflection mode (ATR), by UV/Vis/NIR spectroscopy, by differential scanning calorimetry (DSC) and by tensile tests on unnotched and notched specimen. Due to the damp heat exposition both, physical aging effects like post crystallisation and chemical aging effects like post crosslinking of EVA or macromolecular degradation characterized by yellowing were detected. Especially, the chemical aging effects were significantly affected by the temperature. For Ionomer 1 a loss of UV absorber was detected at the higher temperature. Because of released residual stresses the PMMA/PVDF glazing/backsheet material curled up at 85 °C, 85 % RH. By UV/Vis/NIR spectroscopy additional absorption peaks attributable to degradation products were found in the reflectance spectrum of the backsheet material TPT. Furthermore delaminations of the multilayer TPT film occured after 5000 h at 85 °C. the multilayer PE/PET film exhibited the most significant chemical degradation effects after damp heat testing.