Progressive optimization of the surface passivation of Si solar cells requires access to the elemental composition and chemical bonding characteristics of ultrathin layers and buried interfaces on textured or structured surfaces. The passivation of the rear side of passivated emitter and rear solar cells, for instance, can be realized through AlO_x/SiN_x stacks, which are known to provide an additional field effect passivation on top of the chemical surface passivation. Herein, transmission electron microscopy is used at locally prepared cross-sections of such stacks. Electron energy loss spectroscopy is used to extract depth-resolved information of elemental composition and chemical bonding at nanometer scale. With this, the interfacial excess O fraction, which is crucial for the field effect passivation, is successfully determined for the first time for AlO_x passivation layer systems on industrially produced Si solar cells.

中文翻译：

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通过扫描透射电子显微镜和电子能量损失光谱法在钝化发射极和背面太阳能电池的 AlOx/Si 界面处分析和过量氧调查

硅太阳能电池表面钝化的逐步优化需要获得超薄层的元素组成和化学键合特性，以及纹理或结构化表面上的掩埋界面。例如，可以通过AlO _x /SiN _x实现钝化发射极和背面太阳能电池背面的钝化堆叠，已知在化学表面钝化的顶部提供额外的场效应钝化。在本文中，透射电子显微镜用于此类堆叠的局部制备横截面。电子能量损失光谱用于提取纳米级元素组成和化学键的深度分辨信息。由此，首次成功确定了工业生产的硅太阳能电池上的AlO _x钝化层系统的界面过量 O 分数，这对场效应钝化至关重要。