Raman Spectroscopy Application to Characterize EVA after UV Exposure
| Autor: | Stephanie S. Watson, Xiaohong Gu, Aaron Urbas, Sari Katz |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Materials science
Analytical chemistry 02 engineering and technology 010402 general chemistry 01 natural sciences Thermal expansion symbols.namesake Crystallinity otorhinolaryngologic diseases General Materials Science Wafer Irradiation Composite material chemistry.chemical_classification Moisture Mechanical Engineering Polymer 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences chemistry Mechanics of Materials symbols sense organs 0210 nano-technology Raman spectroscopy Raman scattering |
| Zdroj: | MRS Advances. 1:1191-1196 |
| ISSN: | 2059-8521 |
| DOI: | 10.1557/adv.2015.55 |
| Popis: | Ethylene-vinyl acetate (EVA) is the most commonly used photovoltaic (PV) encapsulant material. As such, it is exposed to UV, thermal cycles, temperature gradients between the glass side and the silicon wafer side, and moisture ingress. The combined effect of all these may lead to different physical and chemical changes of EVA including polymer chain alignment, crystallinity, and crosslinking density, as well as the mechanical stresses resulting from coefficient of thermal expansion (CTE) and aging, thus, reducing the adhesion of EVA and eventually lead to failure of the encapsulation. Measuring the effects of UV exposure on EVA can help in understanding the failure mechanism of PV modules. In this work, we suggest a novel and non-destructive way to measure EVA degradation after UV exposure by using Raman spectroscopy (RS). Samples were exposed to NIST SPHERE with UV irradiation, moisture, and elevated temperatures. The physical and chemical changes as well as the internal stresses were monitored by RS, and the intensities of the corresponding Raman peaks ratio were analyzed. The results have indicated that Raman scattering is a sensitive tool to study EVA encapsulant degradation. |
| Databáze: | OpenAIRE |
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