Effect of the KF post-deposition treatment on grain boundary properties in Cu(In, Ga)Se2 thin films
Effect of the KF post-deposition treatment on grain boundary properties in Cu(In, Ga)Se2 thin films
复制标题
KF 沉积后处理对 Cu(In, Ga)Se2 薄膜晶界性质的影响
作者：
N. Nicoara;T. Lepetit;L. Arzel;S. Harel;N. Barreau;S. Sadewasser
最近，基于各种多晶吸收体（包括钙钛矿、CdTe和Cu（In，Ga）Se 2（CIGS））的薄膜太阳能电池已经实现了显著的功率转换效率改进。通过（沉积后）处理钝化晶界（GB）是实现这一成功的关键步骤。对于CIGS，引入氟化钾后沉积处理（KF-PDT）将其功率转换效率提高到所有多晶太阳能电池的最佳性能。钾在CIGS层中的界面和界面附近区域的直接和间接作用被认为是这种改善的原因。在这里，我们表明，也是有益的修改的KF-PDT的电子性质的GB。我们使用开尔文探针力显微镜研究的KF-PDT对CIGS表面的表面电位的空间分辨成像的效果。我们发现GB的电子性质的一个明显的差异：KF-PDT增加了约70%的GB的能带弯曲，并导致在GB的功函数值的分布较窄。预计KF-PDT对GB电子性质的这种影响有助于用KF-PDT观察到的CIGS薄膜太阳能电池的效率值的提高。
Significant power conversion efficiency improvements have recently been achieved for thin-film solar cells based on a variety of polycrystalline absorbers, including perovskites, CdTe, and Cu(In,Ga)Se2 (CIGS). The passivation of grain boundaries (GBs) through (post-deposition) treatments is a crucial step for this success. For the case of CIGS, the introduction of a potassium fluoride post-deposition treatment (KF-PDT) has boosted their power conversion efficiency to the best performance of all polycrystalline solar cells. Direct and indirect effects of potassium at the interface and interface-near region in the CIGS layer are thought to be responsible for this improvement. Here, we show that also the electronic properties of the GBs are beneficially modified by the KF-PDT. We used Kelvin probe force microscopy to study the effect of the KF-PDT on the CIGS surface by spatially resolved imaging of the surface potential. We find a clear difference for the GB electronic properties: the KF-PDT increases the band bending at GBs by about 70% and results in a narrower distribution of work function values at the GBs. This effect of the KF-PDT on the GB electronic properties is expected to contribute to the improved efficiency values observed for CIGS thin-film solar cells with KF-PDT.
影响因子：
2.8
作者：
Laemmle, Anke;Wuerz, Roland;Powalla, Michael
通讯作者：
Powalla, Michael