Physico-chemical characterization of CuAlSe2 films obtained by reaction, induced by annealing, between Se vapour and Al/Cu/AI…Cu/Al/Cu thin films sequentially deposited

CuAlSe2 thin films have been synthesized by selenization of thin Cu and Al layers sequentially deposited by evaporation under vacuum. The films have been characterized by X-ray diffraction, scanning and transmission electron microscopy, microprobe analysis, photoelectron spectroscopy and Raman diffusion. The results are compared to those obtained with a CuAlSe2 reference powder. It is shown that CuAlSe2 films are obtained with some Cu2−δSe phases present at the surface. These surface phases are suppressed by chemical etching in a KCN solution. At the end of the process, the XRD spectrum demonstrates that textured CuAlSe2 films have been obtained with preferential orientation of the crystallites along the (112) direction. TEM study has shown that both randomly and (112) oriented microcrystallites exist in the layers. The films are nearly stoichiometric, but their surface is quite rough. The Raman patterns are in good accordance with the reference. The XPS spectra show that the binding energies of the elements are in good agreement with bonds of CuAlSe2.