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

作者：David C. Miller, Katherine E. Hurst, Archana Sinha, Jiadong Qian, Stephanie L. Moffitt, Soňa Uličná, Laura T. Schelhas, Peter Hacke · 发表于：Progress in Photovoltaics Research and Applications · 年份：2023 · DOI：10.1002/pip.3690 · 被引用次数：7 · 研究领域：Thin-Film Transistor Technologies、Silicon and Solar Cell Technologies、Integrated Circuits and Semiconductor Failure Analysis

Abstract The direct current bias for photovoltaic (PV) modules interconnected in series‐strings may include both high voltage negative (“HV−”) and positive (“HV+”) polarity with respect to the electrical ground. Multiple degradation modes, resulting in quantifiable optical loss, were found to occur during HV−/HV+ sequential stress, including corrosion of the external glass surface, encapsulant delamination (at its interfaces with the glass and the PV cell), internal haze formation (resulting from a chemical interaction between the glass and the encapsulant), corrosion and migration of the gridlines, and corrosion of the silicon nitride (Si x N y ) antireflective coating on the cell. The effects of these separate modes were examined using monolithic (e.g., glass or PV cell) and laminated‐coupon (glass/encapsulant/glass or glass/encapsulant/cell/encapsulant/backsheet) specimens. Characterizations during and after unbiased accelerated testing at 85°C/85% relative humidity included spectrophotometry, optical microscopy, electron microscopy, and ellipsometry. For some module components (i.e., the glass and the Si x N y coating), the optical performance was determined through iterative analysis of empirical measurements. Concentrating on just their spectral effect, a novel model was then developed to estimate the transfer of light to the PV cell and the return of light from the PV module with simultaneous degradation mechanisms, which was compared with a mini‐module previously subj...