Infrared and Raman microscopies are complementary tools for analyzing the chemical structures of polymer. In this paper, the study is specially devoted to the encapsulant materials of a flexible PV panel. With different characterization methods (optical microscopy, infrared spectroscopy, infrared and Raman microscopy, DSC, TGA), the structure of encapsulation system was characterized: the number and nature of the layers were determined. The materials used and the structure of the complex are especially designed for photovoltaic application. The encapsulation system was further characterized after an accelerated ageing at 80 degrees C/85% RH for 2000 h. The chemical modifications were studied by infrared and Raman microscopies. (C) 2013 Elsevier B.V. All rights reserved,