Abstract Low activation energy (Ea) and wide bandgap (Eg) are essential for (p)-contacts to achieve effective hole collection in silicon heterojunction (SHJ) solar cells. In this work, we study Plasma-Enhanced Chemical Vapor Deposition p-type hydrogenated nanocrystalline silicon oxide, (p)nc-SiOx:H, combined with (p)nc-Si:H as (p)-contact in front/back-contacted SHJ solar cells. We firstly determine the effect of a plasma treatment at the (i)a-Si:H/(p)-contact interface on the thickness-dependent Ea of (p)-contacts. Notably, when the (p)nc-Si:H layer is thinner than 20 nm, the Ea decreases by applying a hydrogen plasma treatment and a very-high-frequency (i)nc-Si:H treatment. Such an interface treatment also significantly reduces the contact resistivity of the (p)-contact stacks (ρc,p), resulting in an improvement of 6.1%abs in fill factor (FF) of the completed cells. Thinning down the (i)a-Si:H passivating layer to 5 nm leads to a low ρc,p (144 mΩ⋅cm2) for (p)-contact stacks. Interestingly, we observe an increment of FF from 72.9% to 78.3% by using (p)nc-SiOx:H layers featuring larger differences between their optical gap (E04) and Ea, which tend to enhance the built-in potential at the c-Si/(i)a-Si:H interface. Furthermore, we observe clear impacts on ρc,p, open-circuit voltage, and FF by optimizing the thicknesses of (p)-contact that influence its Ea. In front junction cells, the vertical and lateral collection of holes is affected by ρc,p of (p)-contact stacks. This observation is also supported by TCAD simulations which reveal different components of lateral contributions. Lastly, we obtain both front and rear junction cells with certified FF well-above 80% and the best efficiency of 22.47%.

中文翻译：

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基于nc-SiO:H的高效硅异质结太阳能电池空穴收集器的设计与优化

摘要 低活化能 (Ea) 和宽带隙 (Eg) 对于 (p) 接触在硅异质结 (SHJ) 太阳能电池中实现有效空穴收集至关重要。在这项工作中，我们研究了等离子体增强化学气相沉积 p 型氢化纳米晶氧化硅，(p)nc-SiOx:H，与 (p)nc-Si:H 结合作为 (p)-contact in front/back-联系 SHJ 太阳能电池。我们首先确定 (i)a-Si:H/(p) 接触界面处的等离子体处理对 (p) 接触的厚度相关 Ea 的影响。值得注意的是，当 (p)nc-Si:H 层薄于 20 nm 时，Ea 通过应用氢等离子体处理和甚高频 (i)nc-Si:H 处理而降低。这种界面处理还显着降低了（p）-接触堆叠（ρc，p）的接触电阻率，从而提高了6。完成单元的填充因子 (FF) 为 1%。将 (i)a-Si:H 钝化层减薄至 5 nm 会导致 (p) 接触堆叠的 ρc,p (144 mΩ⋅cm2) 较低。有趣的是，我们观察到通过使用具有光学间隙 (E04) 和 Ea 之间较大差异的 (p)nc-SiOx:H 层，FF 从 72.9% 增加到 78.3%，这往往会增强 c 处的内置电位-Si/(i)a-Si:H 界面。此外，我们通过优化影响其 Ea 的 (p) 接触的厚度，观察到对 ρc、p、开路电压和 FF 的明显影响。在前结电池中，空穴的垂直和横向收集受 (p) 接触堆叠的 ρc,p 影响。这种观察也得到了 TCAD 模拟的支持，该模拟揭示了横向贡献的不同组成部分。最后，