Abstract Diamond-wire-sawn (DWS) technique has been widely applied in PV industry. However, this technique still has a big challenge when it is used for multi-crystalline silicon (mc-Si) because its reflectivity of DWS mc-Si etched by the conventional acid etching solution (HF/HNO3/H2O system) is quite higher. This paper proposes a metal-free additive texturization method, in which polyethylene glycol (PEG) is added to the HF/HNO3/H2O system to reduce the reaction rate of silicon wafers and improve the wettability of the etching liquid and the surface of mc-Si wafers. The etching points will gradually turn into nanopores instead of worm-like structures due to low reaction rates. Those nanopores form a gradually changed refractive index between silicon and air, which immensely reduces the surface reflectivity of mc-Si wafers. The mc-Si wafers processed in the experiment have an average surface reflectivity of about 16.9% in the wavelength range of 300–1100 nm, which is generally lower than the mc-Si wafers etched by the conventional acid etching process. This technical route has been applied to fabricate the 156 mm × 156 mm DWS mc-Si solar cells, and finally, the conversion efficiency of 19.39% has been obtained. Moreover, this approach matches well with the current PV industrial processes, showing a promising prospect.

中文翻译：

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一种用于金刚石线锯多晶硅片的无金属添加剂制绒方法

摘要 金刚石线锯（DWS）技术已广泛应用于光伏行业。然而，该技术在用于多晶硅（mc-Si）时仍然存在很大的挑战，因为其通过常规酸蚀刻溶液（HF/HNO3/H2O系统）蚀刻的DWS mc-Si的反射率相当高。本文提出了一种无金属添加剂制绒方法，在HF/HNO3/H2O体系中加入聚乙二醇(PEG)，以降低硅片的反应速率，提高蚀刻液和mc-表面的润湿性。硅片。由于低反应速率，蚀刻点将逐渐变成纳米孔而不是蠕虫状结构。这些纳米孔在硅和空气之间形成逐渐变化的折射率，极大地降低了 mc-Si 晶片的表面反射率。实验中处理的 mc-Si 晶片在 300-1100 nm 波长范围内的平均表面反射率约为 16.9%，这通常低于通过常规酸蚀刻工艺蚀刻的 mc-Si 晶片。该技术路线已应用于制造156 mm×156 mm DWS mc-Si太阳能电池，最终获得了19.39%的转换效率。此外，这种方法与当前的光伏工业流程相匹配，显示出广阔的前景。已获得 39%。此外，这种方法与当前的光伏工业流程相匹配，显示出广阔的前景。已获得 39%。此外，这种方法与当前的光伏工业流程相匹配，显示出广阔的前景。