Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-27T01:41:43.506Z Has data issue: false hasContentIssue false

Defects and Recombination Kinetics in Copper Indium Gallium Sulfide Thin Films With Spatially Resolved Luminescence in the μm-scale

Published online by Cambridge University Press:  01 February 2011

Florian Heidemann
Affiliation:
Gottfried H. Bauer
Affiliation:
[email protected], Carl-von-Ossietzky University, Institute of Physics, Oldenburg, Germany
Get access

Abstract

Chalcopyrite Cu(In,Ga)S2 is a promising absorber in thin film solar cells, although the comparable high band gaps so far do not correspond to equivalent high open circuit voltages. We have performed photoluminescence studies on CdS passivated absorber layers deposited on Mo coated soda lime glass. From spectrally and spatially resolved (≤ 1μm) room temperature photoluminescence measurements we have extracted the local splitting of quasi- Fermi levels (EFn-EFp) and local absorption (A(ω)) particularly in the sub bandgap-regime via Planck's generalized law. We observe a substantial negative correlation coefficient between the local sub bandgap/defect absorption and the local (EFn-EFp), which we interpret in terms of the recombination of photogenerated minority carriers (here electrons) via sub bandgap states/deep defects. Moreover we have correlated local PL yields with corresponding values at neighbor sites versus distance (increment analysis). As we find lateral correlation distances in the vicinity of average grain sizes we conclude grains with PL yield and according different splitting of (EFn-EFp) to be independent from one another and be laterally distributed randomly.

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Repins, I., Contreras, M.A., Egaas, B., DeHart, C., Scharf, J., Perkins, C.L., To, B. and Noufi, R., Prog. Photovolt: Res. Appl. 16, 235239 (2008).Google Scholar
2 Klenk, R., Klaer, J., Scheer, R., Lux-Steiner, M.C., Luck, I., Meyer, N. and Rühle, U., Thin Solid Films, 480, 509514 (2005).Google Scholar
3 Klaer, J., Klenk, R. and Schock, H.W., Thin Solid Films, 515, 59295933 (2007).Google Scholar
4 Kaigawa, R., Neisser, A., Klenk, R. and Lux-Steiner, M.C., Thin Solid Films, 415, 266271 (2002).Google Scholar
5 Siemer, K., Klaer, J., Luck, I., Bruns, J., Klenk, R. and Bräunig, D., Sol. Energy Mater. Sol. Cells, 67, 159166 (2001).Google Scholar
6 Ellmer, K., Hinze, J. and Klaer, J., Thin Solid Films, 413, 9297 (2002).Google Scholar
7 Bothe, K., Bauer, G.H. and Unold, T., Thin Solid Films, 403404, 453456 (2002).Google Scholar
8 Taretto, K. and Rau, U., J. Appl. Phys. Phys., 103, 094523 (2008).Google Scholar
9 Würfel, P., J. Phys. C: Solid State Phys., 15, 39673985 (1982).Google Scholar
10 Daub, E. and Würfel, P., Phys. Rev. Lett., 74, 10201023 (1995).Google Scholar
11 Gütay, L. and Bauer, G.H., Thin Solid Films, 517, 22222225 (2009).Google Scholar
12 Gütay, L. and Bauer, G.H., Thin Solid Films, 515, 62126216 (2007).Google Scholar
13 Unold, T., Sieber, I. and Ellmer, K., Appl. Phys. Lett., 88, 213502 (2006).Google Scholar
14 Wächter, M., PhD. Thesis, University of Oldenburg, Germany, 2004.Google Scholar
15 Heidemann, F., Gütay, L., Meeder, A. and Bauer, G.H., Thin Solid Films, 517, 24272430 (2009).Google Scholar
16 Gütay, L., Pomraenke, R., Lienau, C. and Bauer, G.H., Phys. Status Solidi A, 206, 10051008 (2009).Google Scholar