Degradation in photovoltaic encapsulation strength of attachment: Results of the first PVQAT TG5 artificial weathering study

Abstract

Delamination of the encapsulant in photovoltaic (PV) module technology results in immediate optical loss and may enable subsequent corrosion or mechanical damage. The effects of artificial weathering were not previously known; therefore, an empirical study was performed to survey the factors most affecting adhesion, including: the UV source (i.e., Xe or fluorescent lamp(s)); the optical filters for the lamp; the chamber temperature; and the relative humidity. Natural weathering was also performed at locations, including: Golden,

Low-Temperature Graphene-Based Paste for Large-Area Carbon Perovskite Solar Cells

“…Such an R sheet is similar or inferior to the values reported for common transparent conductive oxide (TCO)-based CEs and C-CEs. , Remarkably, a reference paste without graphene shows a 5-fold increase of the resistivity compared to the graphene-based paste (resistivity = 0.35 ÷ 0.06 Ω cm). Thus, graphene-based C-CEs are expected to alleviate the drawback (e.g., low FF) related to the high series resistance of current collectors in large-area solar cells. , In addition, graphene-based films show optimal mechanical properties, which may be beneficial to tolerate thermomechanical stresses associated with natural weathering (day/night cycles, as simulated by the IEC 61215:2016 damp heat test) and metallization–encapsulation processes . As shown in Figure f, they withstand tensile strains before neat fracture >70% (fracture strain of PET), while a reference film without graphene breaks to a tensile strain lower than 10%.…”

“…Thus, graphene-based C-CEs are expected to alleviate the drawback (e.g., low FF) related to the high series resistance of current collectors in large-area solar cells. 74 , 75 In addition, graphene-based films show optimal mechanical properties, which may be beneficial to tolerate thermomechanical stresses associated with natural weathering (day/night cycles, as simulated by the IEC 61215:2016 damp heat test 76 ) 77 and metallization–encapsulation processes. 78 As shown in Figure 2 f, they withstand tensile strains before neat fracture >70% (fracture strain of PET), while a reference film without graphene breaks to a tensile strain lower than 10%.…”

Quantifying optical loss of high‐voltage degradation modes in photovoltaic modules using spectral analysis

“…IHF and gridline corrosion are estimated for changes in absorptance only, limiting their effect on F r . The net effect of encapsulant/ARC c delamination is reduced because of the diminished intensity of the sun at longer wavelengths, in addition to the H 2 O absorption band at ~1130 nm [44] relative to the representative solar‐weighted wavelength spectra (300–1250 nm). Although the change in F r from ARC c corrosion results from the assumed spectra for corroded ρ EVAb/ARCc/Si in Figure 9, F t depends on the absorptance of Si x N y at short wavelengths in Figure 2 and the increased reflectance of the corroded ρ EVAb/ARCc/Si spectra beyond 760 nm.…”

“…Delamination of both the glass/encapsulant and encapsulant/cell interfaces has been observed in fielded PV modules [7,31,32]. A reduction in the adhesion at the glass/encapsulant interface has been shown to result from hot and humid field conditions and DH accelerated testing [44], with and without applied electrical bias [4]. HV+ bias can induce migration of metal ions from the busbars and gridlines on the cell into the encapsulant [10].…”

“…The net effect of encapsulant/ARC c delamination is reduced because of the diminished intensity of the sun at longer wavelengths, in addition to the H 2 O absorption band at $1130 nm [44] relative to the representative solar-weighted wavelength spectra (300-1250 nm).…”