Raman scattering analysis of Cu-poor Cu(In,Ga)Se2 cells fabricated on polyimide substrates: Effect of Na content on microstructure and phase structure - Izquierdo-Roca, V.; Caballero, R.; Fontané, X.; Kaufmann, C.A.; Álvarez-García, J.; Calvo-Barrio, L.; Saucedo, E.; Pérez-Rodríguez, A.; Morante, J.R.; Schock, H.W. (Thin Solid Films, 2011)