This study evaluates the potential of hydrogen‐doped In₂O₃ (IOH) as a transparent back contact material in (Ag_y,Cu_1‐y)(In_1‐x,Ga_x)Se₂ solar cells. It is found that the presence of Na promotes the creation of Ga₂O₃ at the back contact during (Ag_y,Cu_1‐y)(In_1‐x,Ga_x)Se₂ growth. An excessive Ga₂O₃ formation results in a Ga depletion, which extends deep into the absorber layer. Consequently, the beneficial back surface field is removed and a detrimental reversed electrical field establishes. However, for more moderate Ga₂O₃ amounts (obtained with reduced Na supply), the back surface field can be preserved. Characterization of corresponding solar cells suggests the presence of an ohmic back contact, even at absorber deposition temperatures of 550°C. The best solar cell with an IOH back contact shows a fill factor of 74% and an efficiency (η) of 16.1% (without antireflection coating). The results indicate that Ga₂O₃ does not necessarily act as a transport barrier in the investigated system. Observed losses in open circuit voltage (V_OC) as compared to reference samples with a Mo back contact are ascribed to a lower Na concentration in the absorber layer.

中文翻译：

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在（Ag，Cu）（In，Ga）Se2太阳能电池中使用氢掺杂的In2O3薄膜作为透明背接触

这项研究评估了掺氢的In ₂ O ₃（IOH）作为（Ag _y，Cu _1-y）（In _1-x，Ga _x）Se ₂太阳能电池中的透明背接触材料的潜力。发现在（Ag _y，Cu _1-y）（In _1-x，Ga _x）Se ₂生长期间，Na的存在会促进在背接触处Ga ₂ O _3的生成。过量的Ga ₂ O ₃形成导致Ga耗尽，该Ga耗尽深入吸收层。因此，去除了有益的背面电场，并建立了有害的反向电场。但是，对于更适中的Ga ₂ O ₃量（通过减少Na的供应量获得），可以保留背面电场。相应太阳能电池的特性表明，即使在550°C的吸收体沉积温度下，也会存在欧姆背接触。带有IOH背接触的最佳太阳能电池的填充系数为74％，效率（η）为16.1％（无增透膜）。结果表明Ga ₂ O ₃不一定在被调查系统中充当运输障碍。在开路电压（观察到的损失V _OC相比，与钼背接触参考样本）归因于在吸收体层低的Na浓度。