Renewable Energy, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB) , Hahn-Meitner Platz 1, 14109 Berlin, Germany.
Laboratory of Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials and Science and Technology , Überlandstraße 129, 8600 Dübendorf, Switzerland.
ACS Appl Mater Interfaces. 2017 Feb 1;9(4):3581-3589. doi: 10.1021/acsami.6b11892. Epub 2017 Jan 17.
A NaF/KF postdeposition treatment (PDT) has recently been employed to achieve new record efficiencies of Cu(In,Ga)Se (CIGSe) thin film solar cells. We have used a combination of depth-dependent soft and hard X-ray photoelectron spectroscopy as well as soft X-ray absorption and emission spectroscopy to gain detailed insight into the chemical structure of the CIGSe surface and how it is changed by different PDTs. Alkali-free CIGSe, NaF-PDT CIGSe, and NaF/KF-PDT CIGSe absorbers grown by low-temperature coevaporation have been interrogated. We find that the alkali-free and NaF-PDT CIGSe surfaces both display the well-known Cu-poor CIGSe chemical surface structure. The NaF/KF-PDT, however, leads to the formation of bilayer structure in which a K-In-Se species covers the CIGSe compound that in composition is identical to the chalcopyrite structure of the alkali-free and NaF-PDT absorber.
一种 NaF/KF 后沉积处理 (PDT) 最近被用于实现铜铟镓硒 (CIGSe) 薄膜太阳能电池的新纪录效率。我们使用了深度依赖的软和硬 X 射线光电子能谱以及软 X 射线吸收和发射光谱，深入了解了 CIGSe 表面的化学结构以及不同 PDT 对其的影响。我们研究了无碱 CIGSe、NaF-PDT CIGSe 和 NaF/KF-PDT CIGSe 吸收体，这些吸收体都是通过低温共蒸发生长的。我们发现，无碱和 NaF-PDT CIGSe 表面都显示出众所周知的 Cu 贫化 CIGSe 化学表面结构。然而，NaF/KF-PDT 导致形成双层结构，其中 K-In-Se 物种覆盖 CIGSe 化合物，其组成与无碱和 NaF-PDT 吸收体的黄铜矿结构相同。
