Title:	Challenges for Polycarbonate (PC) and Polymethyl methacrylate (PMMA) for the Use as Flexible Front-Sheets in Photovoltaic Modules
Author(s):	S. Feldbacher, A. Macher, G. Oreski
Keywords:	PV Materials, Stability, Characterisation
Topic:	Photovoltaic Modules and BoS Components
Subtopic:	Materials for PV Modules, Durability, Reliability and Accelerated Testing Methods
Event:	8th World Conference on Photovoltaic Energy Conversion
Session:	3DV.3.8
ISBN:	3-936338-86-8
Price:	0,00 EUR
Document(s):	poster

Abstract/Summary:

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Here two transparent polymers films made of PMMA and PC have been selected and the main optical, mechanical and thermo-mechanical properties have been measured. The films then were subjected to artificial accelerated ageing tests and characterized. PMMA exhibits high transparency and an UV stability. The thermal expansion behavior showing anisotropic shrinkage higher than 70°C could be seen as critical due to the formation of internal stresses during lamination. By comparison, PC exhibited constant and very low expansion up to 120°C. However, PC showed strong embrittlement after both aging tests and strong yellowing after xenon weathering. Overall the study confirms both materials in their current state are not usable for PV. Whereas the problem with PMMA is related to its intrinsic thermo-mechanical properties, the biggest challenges for PC are UV stabilization and adhesion to other materials. But these problems can be overcome with suitable UV stabilization and surface modification.