Abstract Nano-texture has the potential to reduce the optical losses of crystalline silicon solar cells. RIE fabricated black silicon enables near zero reflectance across a broad range of wavelengths and the angular dependence has been shown to be superior to existing technologies. However, in front-contact cells which are the current industrial mainstream architecture, the emitter is located on the front textured side and is typically realized by POCl3 diffusion. The interaction of this process with the nano-texture is complex, which makes it challenging to optimise the electrical performance of the phosphorus emitter. This paper studies the impact of in-situ oxidation during emitter formation to the electrical performance of a POCl3 diffused RIE nanotextured emitter surface. Additional corona charge was applied on the ALD SiO2/Al2O3 stack to avoid the limitation on the emitter performance due to non-ideal surface passivation conditions. After saturation with surface charge, the results demonstrate in-situ oxidation to be an effective technique to improve the electrical performance. An emitter recombination factor of 147 fA/cm2 was achieved for a 127 Ω/□ emitter formed on reactive-ion etched sample with surface area enhancement factor and effective slope index of 4.19 and 1.63, respectively. Further paths for improvement are identified, particularly relating to the collection of carriers generated by short wavelength light and how that relates to the shape of the texture used.

中文翻译：

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通过在 POCl3 扩散过程中应用原位氧化改善 RIE 黑硅的发射极性能

摘要 纳米纹理具有降低晶体硅太阳能电池光损耗的潜力。RIE 制造的黑硅能够在广泛的波长范围内实现接近零的反射率，并且角度依赖性已被证明优于现有技术。然而，在当前工业主流架构的正面接触电池中，发射极位于正面纹理侧，通常通过 POCl3 扩散实现。该过程与纳米纹理的相互作用很复杂，这使得优化磷发射器的电性能具有挑战性。本文研究了发射极形成过程中原位氧化对 POCl3 扩散的 RIE 纳米纹理发射极表面电性能的影响。在 ALD SiO2/Al2O3 叠层上施加额外的电晕电荷，以避免由于非理想的表面钝化条件而限制发射极性能。在表面电荷饱和后，结果表明原位氧化是提高电性能的有效技术。对于在反应离子蚀刻样品上形成的 127 Ω/□ 发射极，其表面积增强因子和有效斜率指数分别为 4.19 和 1.63，实现了 147 fA/cm2 的发射极复合因子。确定了进一步的改进途径，特别是与由短波长光产生的载流子的收集以及这与所用纹理的形状如何相关。结果表明原位氧化是提高电性能的有效技术。对于在反应离子蚀刻样品上形成的 127 Ω/□ 发射极，其表面积增强因子和有效斜率指数分别为 4.19 和 1.63，实现了 147 fA/cm2 的发射极复合因子。确定了进一步的改进途径，特别是与由短波长光产生的载流子的收集以及这与所用纹理的形状如何相关。结果表明原位氧化是提高电性能的有效技术。对于在反应离子蚀刻样品上形成的 127 Ω/□ 发射极，其表面积增强因子和有效斜率指数分别为 4.19 和 1.63，实现了 147 fA/cm2 的发射极复合因子。确定了进一步的改进途径，特别是与由短波长光产生的载流子的收集以及这与所用纹理的形状如何相关。