Dresden 2011 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 29: Topical Session TEM VIII
MM 29.1: Vortrag
Mittwoch, 16. März 2011, 15:45–16:00, IFW B
Quantitative TEM-EDX analysis of compositional inhomogeneities in CIGS absorbers — •Isabel Knoke1, Benito Vieweg1, Stefan Jost2, Jörg Palm2, and Erdmann Spiecker1 — 1Center for Nanoanalysis and Electron Microscopy (CENEM), Universität Erlangen-Nuürnberg, Cauerstraße 6, 91058 Erlangen — 2AVANCIS GmbH & Co. KG, Otto-Hahn Ring 6, 81739 München
Thin film solar cells based on the chalcopyrite absorber material Cu(In,Ga)(S,Se)2 are promising candidates for reducing the costs of photovoltaic [1]. However, depending on the fabrication process the absorber may show strong compositional inhomogeneities resulting in local variations of the band gap. Since these inhomogeneities occur on various length scales and both, in horizontal and vertical layer direction, characterization by TEM techniques is difficult because of missing depth information and limited thin area in conventional plan-view and cross-section samples, respectively. A new sample preparation technique overcomes these limitations by a double-wedge geometry that separates depth information in a continuous series of thin slices that are spread over a lateral distance [2]. Application of this preparation technique allows us to perform a significant number of EDX measurements at the same layer height and determine variations in the In/Ga resp. S/Se ratios. Corresponding changes in the lattice constant and band gap are calculated.
[1] J. Palm, V. Probst, F.H. Karg, Solar Energy 77, 757 (2004) [2] E. Spiecker et al., Acta Mater. 55, 3521 (2007)