Abstract An appropriate Ga slope is required in Cu(In,Ga)Se2 (CIGS) film to enhance the cell performance of CIGS thin-film solar cells. In the conventional three-stage-co-evaporation process, the Ga slope was obtained by controlling Ga/In flux during deposition process. However, in two-step process, where a precursor was deposited first and the annealed in a Se environment for mass production, the desirable Ga slope was not achievable with the Ga/In flux control. We observed that the Ga/(Ga+In) ratio was nearly flat in CIGS film for Se-rich precursor and the ratio was nearly zero at surface and very high on bottom side of CISG film for Se-deficient precursor. We were able to generate a CIOGS film with a Ga non-zero Ga surface and desired slope in the bulk by devising a precursor with Se-rich layer on top and Se-deficient layer on bottom, resulting in the enhancement of Cell performance.

中文翻译：

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一种通过控制多层前驱体中Se含量在Cu(In,Ga)Se2薄膜中产生Ga斜率的新方法

摘要 Cu(In,Ga)Se2 (CIGS)薄膜需要适当的Ga斜率来提高CIGS薄膜太阳能电池的电池性能。在传统的三级共蒸发工艺中，Ga斜率是通过控制沉积过程中的Ga/In通量来获得的。然而，在两步法中，先沉积前驱体，然后在 Se 环境中退火以进行大规模生产，通过 Ga/In 通量控制无法实现理想的 Ga 斜率。我们观察到，对于富硒前驱体，CIGS 膜中的 Ga/(Ga+In) 比率几乎是平坦的，而对于缺硒前驱体，该比率在表面几乎为零，而在 CIGS 膜的底部非常高。通过设计顶部富硒层和底部缺硒层的前驱体，我们能够生成具有 Ga 非零 Ga 表面和所需体积斜率的 CIOGS 薄膜，