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DOE OSTI · 2525872

PVDF-based backsheet cracking: Mapping in situ phase evolution by X-ray scattering

Moffitt, Stephanie L. [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States)] (ORCID:0000000259349771)·Uličná, Soňa [National Renewable Energy Laboratory (NREL), Golden, CO (United States)]·Jhang, Song-Syun [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States)]·Pan, Po-Chang [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States)]·Owen-Bellini, Michael [National Renewable Energy Laboratory (NREL), Golden, CO (United States)]·Hacke, Peter [National Renewable Energy Laboratory (NREL), Golden, CO (United States)]·Kempe, Michael D. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)] (ORCID:0000000333120482)·Tracy, Jared [Du Pont de Nemours (E.I.) and Co., Wilmington, DE (United States)]·Choudhury, Kaushik R. [Du Pont de Nemours (E.I.) and Co., Wilmington, DE (United States)]·Schelhas, Laura T. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)] (ORCID:0000000322991864)·Gu, Xiaohong [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States)] (ORCID:0000000288129540)
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Abstract

One of the most common polymers used in commercial photovoltaic backsheets is polyvinylidene fluoride (PVDF). However, recent reports have shown the potential for PVDF-based backsheets to crack and fail prematurely. Previous work has suggested that polymer phase changes play a role in the failure mechanism. Here, in situ wide-angle X-ray scattering maps are used to show that α- to β-phase transformations occur at crack tips in aged PVDF-based backsheets under stretching. Substantial β-phase formation is shown to be associated with strain hardening. In addition, our work demonstrates that β-phase formation is not required for crack growth and only occurs at crack tips when plastic deformation of the PVDF polymer has occurred. In conclusion, the anisotropy in the strength of aged PVDF-based backsheets is linked to the lack of β-phase formation when strain is applied to aged backsheets in the transverse direction.

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14 SOLAR ENERGYPolymer phasePolyvinylidene fluorideSolar panel backsheetsWide-angle X-ray scattering

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Moffitt, Stephanie L. [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States)] (ORCID:0000000259349771), Uličná, Soňa [National Renewable Energy Laboratory (NREL), Golden, CO (United States)], Jhang, Song-Syun [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States)], Pan, Po-Chang [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States)], Owen-Bellini, Michael [National Renewable Energy Laboratory (NREL), Golden, CO (United States)], Hacke, Peter [National Renewable Energy Laboratory (NREL), Golden, CO (United States)], Kempe, Michael D. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)] (ORCID:0000000333120482), Tracy, Jared [Du Pont de Nemours (E.I.) and Co., Wilmington, DE (United States)], Choudhury, Kaushik R. [Du Pont de Nemours (E.I.) and Co., Wilmington, DE (United States)], Schelhas, Laura T. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)] (ORCID:0000000322991864), Gu, Xiaohong [National Institute of Standards and Technology (NIST), Gaithersburg, MD (United States)] (ORCID:0000000288129540). 2024-12-15. PVDF-based backsheet cracking: Mapping in situ phase evolution by X-ray scattering. https://doi.org/10.1016/j.solmat.2024.113355

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