Ultrathin Cu(In, Ga)Se2 solar cells

• Main Authors: Naghavi, N., Jehl, Z., Erfurth, F., Guillemoles, J., Donsanti, F., Gerard, I., Tran-Van, P., Bouttemy, M., Etcheberry, A., Pelouard, J., Collin, S., Colin, C., Pere-Laperne, N., Dahan, N., Greffet, J., Morel, B., Djebbour, Z., Darga, A., Mencaraglia, D., Voorwinden, G., Dimmler, B., Powalla, M., Lincot, D.
• Format: Conference Proceeding
• Language: English
• Subjects: Absorption; Coatings; Etching; Gold; Materials; Optical reflection; Photovoltaic cells
• ISSN: 0160-8371
• DOI: 10.1109/PVSC.2011.6185938

Within the UltraCIS project we have started to explore the possibility of reducing down the thickness of the Cu(In, Ga)Se 2 (CIGSe) layer to the sub-micron level (0.1μm) while maintaining a high efficiency level of solar cells. The three main approaches we used are: - Reducing the CIGSe thickness by chemical etching combining the thickness reduction and smoothing effect of the absorber. Efficiency higher than 10 % on small area cells with an absorber thickness of 0.5 μm are obtained. Losses were attributed exclusively to the reduced photocurrent and the loss on texturation of the absorber - Optical management by front contact texturation or by replacement of the back contact by the "lift-off" of CIGSe layer from the Mo layer and deposition of a new reflective back contact. - Application of plasmonic structures to CIGSe solar cells enabling light confinement at the subwavelength scale.