Raman scattering analysis of Cu-poor Cu(In,Ga)Se2 cells fabricated on polyimide substrates: Effect of Na content on microstructure and phase structure - Schock, HW; Morante, JR; Perez Rodriguez, A; Calvo Barrio, L; Álvarez García, J; Kaufmann, CA; Fontané, X; Izquierdo Roca, V; Caballero Mesa, Ana Raquel (Thin Solid Films, 2011)