J. A. García Valenzuela, D. Cabrera-German, M. Cota-Leal, G. Suárez-Campos, M. Martínez-Gil, F. Romo-García, M. R. Baez-Gaxiola, M. Sotelo-Lerma, J. Andreu, and J. Bertomeu, Modulation of argon pressure as an option to control transmittance and resistivity of ZnO:Al films deposited by DC magnetron sputtering: on the dark yellow films at 10-7 Torr base pressures, Rev. Mex. Fís. 64, (2018).