In this article, we report on the properties of indium tin oxide (ITO) deposited on thin-film silicon layers designed for the application as carrier selective contacts for silicon heterojunction (SHJ) solar cells. We find that ITO deposited on hydrogenated nanocrystalline silicon (nc-Si:H) layers presents a significant drop on electron mobility ${\mu} _{{\rm{e}}}$ in comparison to layers deposited on hydrogenated amorphous silicon films (a-Si:H). The nc-Si:H layers are not only found to exhibit a larger crystallinity than a-Si:H, but are also characterized by a considerably increased surface rms roughness. As we can see from transmission electron microscopy (TEM), this promotes the growth of smaller and fractured features in the initial stages of ITO growth. Furthermore, secondary ion mass spectrometry profiles show different penetration depths of hydrogen from the thin film silicon layers into the ITO, which might both influence ITO and device passivation properties. Comparing ITO to aluminum doped zinc oxide (AZO), we find that AZO can actually exhibit superior properties on nc-Si:H layers. We assess the impact of the modified ITO R_sh on the series resistance $R_{s}$ of SHJ solar cells with >23% efficiency for optimized devices. This behavior should be considered when designing solar cells with amorphous or nanocrystalline layers as carrier selective contacts.

中文翻译：

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硅层对硅异质结太阳能电池中 ITO 和 AZO 生长的影响

在本文中，我们报告了沉积在薄膜硅层上的氧化铟锡 (ITO) 的特性，该硅层专为用作硅异质结 (SHJ) 太阳能电池的载流子选择性接触而设计。我们发现沉积在氢化纳米晶硅 (nc-Si:H) 层上的 ITO 电子迁移率显着下降${\mu} _{{\rm{e}}}$与沉积在氢化非晶硅膜 (a-Si:H) 上的层相比。发现 nc-Si:H 层不仅表现出比 a-Si:H 更大的结晶度，而且还具有显着增加的表面均方根粗糙度。正如我们从透射电子显微镜 (TEM) 中看到的那样，这促进了 ITO 生长初始阶段更小和断裂特征的生长。此外，二次离子质谱图显示氢从薄膜硅层进入 ITO 的不同渗透深度，这可能会影响 ITO 和器件钝化性能。将 ITO 与掺杂铝的氧化锌 (AZO) 进行比较，我们发现 AZO 实际上可以在 nc-Si:H 层上表现出优异的性能。我们评估修改后的 ITO 的影响电阻串联电阻上的_sh$R_{s}$SHJ 太阳能电池的效率 > 23%，用于优化设备。在设计具有非晶或纳米晶层作为载流子选择性接触的太阳能电池时，应考虑这种行为。