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Chirila, A., Buecheler, S., Pianezzi, F., Bloesch, P., Gretener, C., Uhl, A.R., Fella, C., Kranz, L., Perrenoud, J., Seyrling, S., Verma, R., Nishiwaki, S., Romanyuk, Y.E., Bilger, G. and Tiwari, A.N. (2011) Highly Efficient Cu(In,Ga)Se2 Solar Cells Grown on Flexible Polymer Films. Nature Materials, 10, 857-861.
https://doi.org/10.1038/nmat3122

has been cited by the following article:

• TITLE: Guidelines for Optimization of the Absorber Layer Energy Gap for High Efficiency Cu(In,Ga)Se2 Solar Cells

  AUTHORS: N. Severino, N. Bednar, N. Adamovic

  KEYWORDS: Solar Cell, Thin-Film, Simulation, Material Modelling

  JOURNAL NAME: Journal of Materials Science and Chemical Engineering, Vol.6 No.4, April 29, 2018

  ABSTRACT: This work investigates in-depth the effects of variation of the compositional ratio of the absorber layer in Cu(In,Ga)Se2 (CIGS) thin-film solar cells. Electrical simulations were carried out in order to propose the most suitable gallium double-grading profile for the high efficiency devices. To keep the model as close as possible to the real behavior of the thin film solar cell a trap model was implemented to describe the bulk defects in the absorber layer. The performance of a solar cell with a standard CIGS layer thickness (2 μm) exhibits a strong dependence on the front grading height (decreasing band gap toward the middle of the CIGS layer). An absolute gain in the efficiency (higher than 1%) is observed by a front grading height of 0.22. Moreover, simulation results show that the position of the plateau (the region characterized by the minimum band gap) should be accurately positioned at a compositional ratio of 20% Ga and 80% In, which corresponds to the region where a lower bulk defect density is expected. The developed model demonstrates that the length of the plateau is not playing a relevant role, causing just a slight change in the solar cell performances. Devices with different absorber layer thicknesses were simulated. The highest efficiency is obtained for a CIGS thin film with thicknesses between 0.8 and 1.1 μm.