Formation of a K-In-Se Surface Species by NaF/KF Postdeposition Treatment of Cu(In,Ga)Se2 Thin-film Solar Cell Absorbers
Document Type
Article
Publication Date
1-1-2017
Publication Title
ACS Applied Materials and Interfaces
Volume
9
Issue
4
First page number:
3581
Last page number:
3589
Abstract
A NaF/KF postdeposition treatment (PDT) has recently been employed to achieve new record efficiencies of Cu(In,Ga)Se2 (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. © 2017 American Chemical Society.
Language
english
Repository Citation
Handick, E.,
Reinhard, P.,
Wilks, R. G.,
Pianezzi, F.,
Kunze, T.,
Kreikemeyer Lorenzo, D.,
Weinhardt, L.,
Blum, M.,
Yang, W.,
Gorgoi, M.,
Ikenaga, E.,
Gerlach, D.,
Ueda, S.,
Yamashita, Y.,
Chikyow, T.,
Heske, C.,
Buecheler, S.,
Tiwari, A. N.,
Bär, M.
(2017).
Formation of a K-In-Se Surface Species by NaF/KF Postdeposition Treatment of Cu(In,Ga)Se2 Thin-film Solar Cell Absorbers.
ACS Applied Materials and Interfaces, 9(4),
3581-3589.
http://dx.doi.org/10.1021/acsami.6b11892