Study of technological conditions to grow nanostructured CuO thin films when using microwave activated chemical bath deposition
A. Benedit-Cárdenas, B. Gonzalez, L. Zamora-Peredo, C. Laza, M. Díaz-Solís
J. Hernández-Torres, F. Forcade, E. Vigil
Physics Faculty, University of Havana, Cuba
Materials Science and Technology Institute (IMRE), University of Havana, Cuba
Micro and Nanotechnology Research Center, University of Veracruz, Mexico
CuO nanostructured films are attractive for several applications like solar cells, water splitting and different types of sensors. Its bandgap increases from 1.2 eV to over 1.5 eV for nano-morphologies. This makes it interesting for band engineering, sometimes required to improve device characteristics. CuO films have been deposited at low temperatures and in a few minutes. A diluted homogeneous aqueous solution of Cu(II) acetate is used as precursor. The CuO layers obtained are very well adhered to FTO conducting glass, as well as, to optical glass, both used as substrates. Higher quality films grow on the FTO conducting glass, which corroborates the preferential heating of the FTO by microwaves, which creates a temperature gradient and favors film growth. Films are characterized with SEM, XRD, as well as, Raman and optical transmission spectroscopies. Crystal size increases with the number of deposition processes while the bandgap decreases.