J. Sastré-Hernández, M. Calixto, M. Tufiño-Velázquez, G. Contreras-Puente, A. Morales-Acevedo, G. Casados-Cruz, M. Hernández-Pérez, M. Albor-Aguilera, and R. Mendoza-Pérez, Cu(In,Ga)Se$_{2}$ thin films processed by co-evaporation and their application into solar cells, Rev. Mex. Fís. 57, (2011).