Impact of a RbF Postdeposition Treatment on the Electronic Structure of the CdS/Cu(In,Ga)Se2 Heterojunction in High-Efficiency Thin-Film Solar Cells
Document Type
Article
Publication Date
1-1-2017
Publication Title
ACS Energy Letters
Volume
2
Issue
10
First page number:
2383
Last page number:
2387
Abstract
Recently, a world-record efficiency of 22.6% was achieved by applying a RbF postdeposition treatment (PDT) on a Cu(In,Ga)Se2 (CIGSe) thin-film solar cell absorber surface. Here, we study the impact of this RbF-PDT on the electronic structure of the CIGSe surface and the CdS/CIGSe interface using ultraviolet and X-ray photoelectron spectroscopy (UPS and XPS), as well as inverse photoemission spectroscopy (IPES). After RbF-PDT, we find a small downward shift of the band edges, while the surface band gap value itself is not affected. In addition, a further downward band bending in the CIGSe absorber is observed upon formation of the RbF-PDT CdS/CIGSe interface. We derive a flat conduction band alignment between the RbF-PDT CIGSe absorber and the CdS buffer, commensurate with the high efficiencies of solar cell devices prepared with RbF-PDT. © 2017 American Chemical Society.
Language
english
Repository Citation
Hauschild, D.,
Kreikemeyer Lorenzo, D.,
Jackson, P.,
Friedlmeier, T. M.,
Hariskos, D.,
Reinert, F.,
Powalla, M.,
Heske, C.,
Weinhardt, L.
(2017).
Impact of a RbF Postdeposition Treatment on the Electronic Structure of the CdS/Cu(In,Ga)Se2 Heterojunction in High-Efficiency Thin-Film Solar Cells.
ACS Energy Letters, 2(10),
2383-2387.
http://dx.doi.org/10.1021/acsenergylett.7b00720