Abstract In this paper, silicon rich polycrystalline silicon carbide (poly-SiCx) thin films were prepared for passivating contact of silicon solar cells. The effect of different carbon doping ratios R [methane flow (sccm)/silane flow (sccm)] and the annealing temperatures on the passivation quality was investigated. The lifetime test showed that, given a lower annealing temperature, the passivation quality of poly-SiCx thin films was very poor at R over 0.2, and it can be improved by elevating the annealing temperature. The effective lifetime of over 1.8 ms can be obtained with implied open-circuit voltages (iVoc) of 715 mV and saturated dark current (J0) of 18 fA/cm2. The microstructure and optical property of poly-SiCx films was studied by Raman spectra, X-ray photoelectron spectroscopy and UV-VIS spectrophotometer. The results showed that the incorporation of carbon lowered the crystalline fraction of poly-SiCx and a higher annealing temperature was needed to achieve high crystallinity. The optical band gap of poly-SiCx was widened with increase in R, and got up to 2.3eV when R was 0.4. A proof-of-concept top/rear TOPCon solar cells, featuring a N+-poly-SiCx (R = 0.2) front contact, was fabricated to demonstrate the potential of this SiCx passivation contact. The decrease in the parasitic absorption of light at the front side resulted in higher photogenerated current. And the conversion efficiency of 20.17% was achieved.

中文翻译：

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多晶碳化硅薄膜作为硅太阳能电池钝化触点的应用

摘要 本文制备了富硅多晶碳化硅（poly-SiCx）薄膜，用于硅太阳能电池的钝化接触。研究了不同碳掺杂比 R [甲烷流量 (sccm)/硅烷流量 (sccm)] 和退火温度对钝化质量的影响。寿命测试表明，在较低的退火温度下，当 R 超过 0.2 时，poly-SiCx 薄膜的钝化质量很差，可以通过提高退火温度来改善。使用 715 mV 的隐含开路电压 (iVoc) 和 18 fA/cm2 的饱和暗电流 (J0) 可以获得超过 1.8 ms 的有效寿命。采用拉曼光谱、X射线光电子能谱和紫外可见分光光度计研究了poly-SiCx薄膜的微观结构和光学性能。结果表明，碳的掺入降低了多晶碳化硅的结晶分数，需要更高的退火温度来实现高结晶度。poly-SiCx的光学带隙随着R的增加而变宽，当R为0.4时达到2.3eV。制造具有 N+-poly-SiCx (R = 0.2) 前触点的概念验证顶部/背面 TOPCon 太阳能电池，以展示该 SiCx 钝化触点的潜力。正面对光的寄生吸收的减少导致更高的光生电流。并且实现了20.17%的转换效率。当 R 为 0.4 时为 3eV。制造具有 N+-poly-SiCx (R = 0.2) 前触点的概念验证顶部/背面 TOPCon 太阳能电池，以展示该 SiCx 钝化触点的潜力。正面对光的寄生吸收的减少导致更高的光生电流。并且实现了20.17%的转换效率。当 R 为 0.4 时为 3eV。制造具有 N+-poly-SiCx (R = 0.2) 前触点的概念验证顶部/背面 TOPCon 太阳能电池，以展示该 SiCx 钝化触点的潜力。正面对光的寄生吸收的减少导致更高的光生电流。并且实现了20.17%的转换效率。