Nondestructive characterization of polymeric components of silicon solar modules by near-infrared absorption spectroscopy (NIRA)

• Published in: Solar energy materials and solar cells Vol. 216; p. 110702
• Main Authors: Stroyuk, Oleksandr, Buerhop-Lutz, Claudia, Vetter, Andreas, Hauch, Jens, Brabec, Christoph J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2020; Elsevier BV
• Subjects: Absorption spectroscopy; Acetic acid; Backsheet; Composition; Degradation; Encapsulant; Encapsulation; Ethylene vinyl acetates; I.R. radiation; Infrared absorption; Infrared spectroscopy; Modules; Near infrared radiation; Near infrared spectroscopy; Nondestructive testing; Photovoltaics; Polymers; Raman spectroscopy; Silicon; Silicon solar modules; Spectrum analysis; Vinyl acetate; Near infrared spectroscopy; Encapsulant; Backsheet; Raman spectroscopy; Silicon solar modules; Photovoltaics
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2020.110702

Degradation of the encapsulation of solar modules is a crucial problem and, accordingly, tools for assessing and understanding the according degradation is an important research topic. Here, we suggest near-infrared absorption spectroscopy (NIRA) as a tool that has a strong potential to determine non-invasively the composition of encapsulant and backsheet in typical commercial solar modules. Correct polymer identification by NIRA was supported by Raman spectral microscopy of the backsheet air sides and cross sections, with a hundred solar modules of different manufacturers analyzed by both spectroscopic methods. Furthermore, a specific NIRA measurement regime of the ethylene vinyl acetate encapsulant is presented, which potentially allows to probe the composition of the encapsulant non-destructively under lab conditions but also on silicon solar modules in the field installed outdoors. The present report shows NIRA to be a powerful method for non-destructive analysis of backsheets and encapsulants of photovoltaic silicon modules. [Display omitted] •Near infrared absorption (NIRA) is used for analysis of solar modules backsheets.•Complex polymer backsheet cross sections are analyzed by multispectral Raman imaging.•NIRA allows non-destructive determination of backsheet and encapsulant composition.•A new method of NIRA analysis of ethylene vinyl acetate encapsulant is proposed.