Abstract In this study, we present detailed theoretical and experimental investigations on full-area alloying from screen-printed aluminum pastes on silicon surfaces for solar cell applications. We introduce a simple analytical model for the description of the alloying process derived from existing models for evaporated Al layers, which we adapt to printed Al pastes. Thereby, we particularly account for the recrystallization of Si within the paste particles, which we refer to as parasitic Si recrystallization. Applying our model, we demonstrate good accordance of calculated with measured eutectic layer thicknesses. We show that the model can be versatilely used to investigate screen-printed Al-alloyed contacts in detail: We demonstrate that the latent heat of the Al paste significantly influences the alloying process. Thus, the effective peak temperature of the alloying process can be several 100 °C below the set peak temperature of the firing furnace. By combining calculations of the effective peak temperature with measurements of the Al doping concentration, we determine a parameterization of the solid solubility of Al in Si down to the eutectic temperature of 577 °C. Our investigations therefore provide improved understanding of alloying from printed Al pastes and enable the specific optimization of Al-alloyed contacts.

中文翻译：

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硅表面丝网印刷铝浆合金化的定量理论和实验分析

摘要 在这项研究中，我们对用于太阳能电池应用的硅表面丝网印刷铝浆的全面积合金化进行了详细的理论和实验研究。我们引入了一个简单的分析模型，用于描述源自蒸发铝层的现有模型的合金化过程，我们将其应用于印刷铝浆。因此，我们特别考虑了浆料颗粒内 Si 的再结晶，我们将其称为寄生 Si 再结晶。应用我们的模型，我们证明了与测量的共晶层厚度计算结果的良好一致性。我们表明该模型可广泛用于详细研究丝网印刷的铝合金触点：我们证明铝糊的潜热显着影响合金化过程。因此，合金化过程的有效峰值温度可以比烧成炉设定的峰值温度低几百℃。通过将有效峰值温度的计算与 Al 掺杂浓度的测量值相结合，我们确定了 Al 在 Si 中的固溶度参数化，低至 577 °C 的共晶温度。因此，我们的研究提高了对印刷铝浆合金化的理解，并使铝合金触点的具体优化成为可能。