Evaluation of impedance spectroscopy as a tool to characterize performance losses in silicon photovoltaics

近年来，新的硅光伏技术得到了发展，如PERC（钝化发射极后触点）电池。这些技术出现了新的失效机制，如光和高温诱导降解（LeTID）和钝化层降解。因此，需要新的表征方法来评估制造过程和现场的这些损失机制。该项目将评估阻抗谱作为一种非破坏性技术来表征由加拿大太阳能公司生产的硅PERC电池和组件的降解机制和性能损失。阻抗谱（Impedance spectroscopy， IS）利用频率变化的交流信号来测量电气系统的阻抗并确定等效电路。等效电路的变化可能与性能损失和电池退化有关。一种用于识别特定降解机制的非破坏性技术将补充现有技术，并将被加拿大太阳能公司用于进一步改进其制造工艺和产品质量，从而可以交付给客户。这可以转化为增加的全球市场份额和扩大加拿大的就业基础。重要的是，光伏发电是一种环保的可再生能源，可以帮助满足加拿大的能源需求。

New silicon photovoltaic technologies have been developed in recent years, such as PERC (Passivated EmitterRear Contact) cells. New failure mechanisms have appeared for these technologies, such as Light and ElevatedTemperature Induced Degradation (LeTID) and passivation layer degradation. New characterization approachesare therefore required to assess these loss mechanisms during the manufacturing process and in the field. Thisproject will assess impedance spectroscopy as a non-destructive technique to characterize degradationmechanisms and performance losses in the silicon PERC cells and modules manufactured by Canadian SolarInc. Impedance spectroscopy (IS) uses an AC signal with varying frequency to measure the impedance of anelectrical system and determine an equivalent circuit. Changes in the equivalent circuit can be associated withperformance losses and cell degradation. A non destructive technique for identifying specific degradationmechanisms would complement existing techniques and would be used by Canadian Solar Inc. to furtherimprove its manufacturing processes and the quality of the products it can deliver to its customers. This couldtranslate to an increased global market share and expanded employment base in Canada. Importantly,photovoltaics are an environmentally friendly renewable energy source that can help meet Canada's energydemands.