Surface Off-Stoichiometry of CuInS2 Thin-Film Solar Cell Absorbers

Marcus Baer (1, 2, 3) , Joachim Klaer (1) , Roberto Felix (1) , Nicolas Barreau (4) , Lothar Weinhardt (3, 5) , Regan G. Wilks (1) , Clemens Heske (3, 5, 6) , Hans-Werner Schock (1)

1 HZB - Solar Energy Division, Berlin
2 BTU - Institut fur Physik und Chemie, Cottbus
3 Department of Chemistry, Las Vegas
4 IMN - Institut des Matériaux Jean Rouxel
5 Synchrotron Light Source ANKA
6 Institute for Chemical Technology and Polymer Chemistry

X-ray photoelectron and x-ray-excited Auger electron spectroscopy was used to investigate the chemical surface structure of CuInS2 thin-film solar cell absorbers. We find that the [In]/[Cu] surface composition can vary between 1.6 (± 0.4) and 3.7 (± 0.7), depending on relatively minor variations in the absorber formation process and/or whether additional wet-chemical treatments are performed. These variations are primarily due to differences in the Cu surface concentration. The corresponding change of the modified In Auger parameter is interpreted as being indicative for a change of the chemical environment of In as a function of Cu off-stoichiometry.

Mots clés: Chalcopyrite thin-film solar cell; surface composition; wet-chemical treatment; X-ray photoelectron spectroscopy

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Marcus Baer, Joachim Klaer, Roberto Felix, Nicolas Barreau, Lothar Weinhardt, et al.. Surface Off-Stoichiometry of CuInS2 Thin-Film Solar Cell Absorbers. IEEE Journal of Photovoltaics, 2013, 3 (2), pp.828. ⟨10.1109/JPHOTOV.2012.2228299⟩. ⟨hal-00981718⟩