Impact of environmental conditions on the chemical surface properties of Cu(In,Ga)(S,Se){sub 2} thin-film solar cell absorbers

Journal Article · Wed May 14 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4876257· OSTI ID:22275543

Meyer, F. ^[1]; Pohlner, S.; Lechner, R.; Dietmüller, R.; Palm, J. ^[2]; Heske, C. ^[3]; Reinert, F. ^[1]

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1. Experimental Physics VII, University of Würzburg, Am Hubland, 97074 Würzburg (Germany)
2. AVANCIS GmbH and Co. KG, Otto-Hahn-Ring 6, 81739 Munich (Germany)
3. Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

Environmentally driven aging effects play a crucial role in thin-film solar cells based on Cu(In,Ga)(S,Se){sub 2}, both for long-term stability and short air exposure during production. For a better understanding of such effects, Cu(In,Ga)(S,Se){sub 2} absorber surfaces were investigated by x-ray photoelectron and Auger electron spectroscopy after exposure to different environmental conditions. Identical absorbers were stored in a nitrogen atmosphere, in damp heat, and under ambient conditions for up to 14 days. We find varying degrees of diffusion of sulfur, copper, and sodium towards the surface, with potential impact on the electronic surface structure (band gap) and the properties of the interface to a buffer layer in a solar cell device. Furthermore, we observe an oxidation (in decreasing order) of indium, copper, and selenium (but no oxidation of sulfur). And finally, varying amounts of carbon- and oxygen-containing adsorbates are found. In particular, the findings suggest that, for ambient air exposure, sodium carbonate is formed at the surface.

• OSTI ID: 22275543
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
AUGER ELECTRON SPECTROSCOPY
CARBON
COPPER
DIFFUSION
ELECTRONIC STRUCTURE
GALLIUM SULFIDES
INDIUM
INDIUM SELENIDES
INTERFACES
LAYERS
NITROGEN
OXIDATION
OXYGEN
SELENIUM
SODIUM
SODIUM CARBONATES
SULFUR
SURFACE PROPERTIES
SURFACES
THIN FILMS