A total of 16 analytical methods, spanning from classical solvent extraction over different thermo-analytic and mechanical approaches to acoustic and optical spectroscopy, have been evaluated as to their ability to determine the crosslinking state of ethylene vinyl acetate (EVA), the prevailing encapsulant for photovoltaics applications. The key objective of this work was to create a systematic and comprehensive comparison, using a unified set of traceable test samples covering the full range of realistically occurring degrees of EVA crosslinking. A majority number of these tested methods proved fundamentally suitable for detecting changes in the polymer properties during crosslinking based on the effect e.g. its mechanical properties or its crystallinity. Interestingly, when investigated in detail, most of the methods showed mutually different dependencies on the lamination time, indicating a complex range of effects of the chemical crosslinking on the properties and behaviour of the material. Furthermore, Raman spectroscopy could be identified as a potential new method for measuring the degree of crosslinking in-line in the PV module manufacturing process, thus providing an interesting approach for improving process control in PV module processing

This work summarizes various degradation mechanisms relevant for perovskite photovoltaics on different levels from the single layers over (tandem) solar cells to solar modules hereof and their mitigation strategies to enable reliable solar modules.

Various types of next‐generation encapsulation films based on polyolefins have recently been introduced and could attract market attention. These material innovations can be classified as polyolefin elastomer (POE) and thermoplastic polyolefin (TPO) encapsulants, both of which consist of a polyethylene backbone with different side groups. The main advantage of these materials is the replacement of the vinyl acetate side groups of state‐of‐the‐art encapsulant ethylene vinyl acetate (EVA) so that acetic acid cannot be formed. The main objective of this paper is to investigate the material properties of next‐generation encapsulant films and compare them to an EVA reference. Two commercially available EVA alternatives (POE and TPO) have been selected. The material properties of single films as well as the electrical performance of test modules using these different encapsulants were investigated. The different films show comparable optical, thermal and thermo‐mechanical properties, with slight differences in UV transparency and melting temperatures. Only shear viscosity values are higher for TPO than for POE and EVA, which requires adaption of the photovoltaic (PV) module lamination parameters. The test modules comprising the different encapsulation films show minor differences in the electrical performance after manufacturing; upon accelerated aging, no significant power loss is observed. But compared to TPO or POE, after 3000 h of damp heat exposure, test modules with EVA show the beginning of corrosion effects at the silver grid and above the ribbons. Based on the results, it can be stated that the new polyolefin encapsulation materials show great potential to be a valid replacement for EVA.