Recent Developments of High Efficiency Micromorph tandem solar cells in KAI-M PECVD reactors

• DOI: 10.4229/26theupvsec2011-3bo.2.6
• Publication Date: 2010-10-28
• Authors: Kroll, U.; Meier, J.; Fesquet, L.; Steinhauser, J.; Benagli, S.; Orhan, J.B; Wolf, B.; Borrello, D.; Castens, L.; Djeridane, Y.; Multone, X.; Choong, G.; Domine, D.; Boucher, J.-F.; Madliger, P.-A.; Marmelo, M.; Monteduro, G.; Dehbozorgi, B.; Romang, D.; Omnes, E.; Chevalley, M.; Charitat, G.; Pomey, A.; Vallat, E.; Marjanovic, S.; Kohnke, G.; Koch, K.; Liu, J.; Modavis, R.; Thelen, D.; Vallon, S.; Zakharian, A.; Weidman, D.
• Keywords: 0103 physical sciences; Thin Film Solar Cells; Amorphous and Microcrystalline Silicon Solar Cells; 01 natural sciences; 7. Clean energy

26th European Photovoltaic Solar Energy Conference and Exhibition; 2340-2343<br/>The use of textured glass substrates in the fabrication of Micromorph tandem thin film silicon cells is shown to improve light-trapping, as evidenced by increased bottom cell EQE, and this results in cell efficiency improvements superior to those previously reported. This work utilizes LPCVD ZnO coated textured glass substrates having very high haze values of around 80%, most notably in the wavelength range where the microcrystalline cell possesses a strong spectral response. A 1000 hour light-soaked stable efficiency of 12.16% has been demonstrated and an efficiency of 12.34% after 700 hours of light-soaking has also been measured. In addition, initial efficiencies as high as 14.4% were recently achieved. These results were obtained using substrates that result in a 7.3% bottom cell current gain relative to cells fabricated with flat glass substrates. Textures enabling still higher bottom cell current gains of up to 13.9% as compared to non-textured glass have been identified.<br/>