We investigate the role of the silicon surface and orientation on double‐sided TOPCon solar cells properties. The solar cells of front and rear, (p) and (n), poly‐Si/SiO_x stack, fabricated on polished surfaces oriented 〈100〉 and 〈111〉 and pyramid textured surfaces, are characterized as a function of the thickness of an ultrathin SiO_x layer, controlled at atomic scale from one‐ to four‐cycle atomic layer deposition (ALD). Our findings underline that the optimized thickness of the ultrathin SiO_x is about 1.1 ± 0.1 nm, corresponding to a two‐cycle ALD, regardless of the surface and orientation of the c‐Si substrate. The open‐circuit voltage is about 10 mV higher on the polished 〈100〉‐oriented surface, associated with lower defect density at the interface of SiO_x/c‐Si. On the other hand, the contact resistance is much lower, about 0.45 Ω/cm², on the polished 〈111〉‐oriented surface. On textured surfaces, we demonstrate a photoconversion efficiency of 19.1% for the double‐sided TOPCon structure strictly for a SiO_x thickness with two‐cycle ALD, which underlines the importance of the ALD technique for the precise control of the ultrathin SiO_x thickness on textured surface.

中文翻译：

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抛光过的<100>和<111>或有纹理的硅表面对双面TOPCon太阳能电池效率的作用

我们研究了硅表面和取向对双面TOPCon太阳能电池性能的作用。正面和背面的太阳能电池（p）和（n），是在朝向<100>和<111>的抛光表面以及棱锥纹理表面上制造的多晶硅-SiO / SiO _x叠层，其特征是厚度的函数一种超薄的SiO _x层，可在原子级范围内控制从一到四周期的原子层沉积（ALD）。我们的发现表明，无论c-Si衬底的表面和方向如何，超薄SiO _x的最佳厚度约为1.1±0.1 nm，相当于两周期ALD。抛光后的<100>取向表面的开路电压大约高10 mV，这与SiO2界面处的缺陷密度较低有关_x / c-Si。另一方面，在抛光的<111>取向表面上的接触电阻要低得多，约为0.45Ω/ cm ²。在带纹理的表面上，我们证明了双面TOPCon结构的光转换效率严格用于带有两次循环ALD的SiO _x厚度，这突出了ALD技术对于精确控制超薄SiO _x厚度的重要性。纹理的表面。