多晶硅太阳电池所使用的多晶硅材料往往因铸造过程中温度、应力等方面控制不佳,导致晶体缺陷形成.本文通过研究"黑丝"电池片以及点状烧穿电池片这两种在电学性能上表现为严重的反向线性漏电的异常电池片,对比观察其异常所处位置的表面及其解理断面的微观结构,发现导致这两种反向漏电现象出现的本质原因是由于其所处位置的硅片结构存在位错或其他晶体缺陷.这种由于晶体缺陷导致的反向漏电现象会使电池在工作过程中局部过热,给光伏发电系统带来巨大隐患.%Multicrystaline silicon materials used for solar cells are usually under poor control of temperature and stress during the casting which may induce defects. Two kinds of abnormal solar cells, "black yarn" solar cells and dotted burnthrough solar cells, were studied in this paper. These two solar cells show severe reverse linear shunt current on the electrical properties. By observing the microstructures of the surface and cleavage plane on the abnormal areas, we find the ultimate reason of these two kinds of reverse currents is that there are dislocations or other crystal defects in the abnormal areas. The reverse current caused by defects could lead to local overheating of the solar cells under operation. This phenomenon may bring huge risk to the photovoltaic power generation systems.
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