Cu–Ga–Se thin films prepared by a combination of electrodeposition and evaporation techniques

Cu–Ga–Se thin films were prepared using a combination of electrodeposition and evaporation techniques. A Cu–Se/Mo/glass precursor thin film was first prepared by galvanostatic electrodeposition. On top of this film three different thicknesses of Ga were deposited by evaporation. The Cu–Ga–Se thin films were formed by annealing the Ga/Cu–Se/Mo/glass thin film configuration in a tubular chamber with Se powder, at different temperatures. Thin films were characterized by X-ray diffraction (XRD), photocurrent spectroscopy (PS), inductively coupled plasma (ICP) analysis, and scanning electron microscopy (SEM). The detailed analysis from X-ray reveals that after annealing at 550 °C the CuGaSe2 phase is formed when the thickness of Ga is 0.25 μm, however at 0.5 μm and 1.0 μm Ga the formation of CuGa3Se5 and CuGa5Se8 phases is observed respectively. Band gap values were obtained using photocurrent spectroscopy.

► CuGaSe2, CuGa3Se5 and CuGa5Se8 phases were prepared from Ga-evaporate on Cu2Se3 thin films. ► Band gap values from 1.63 to 1.79 eV of Cu–Ga–Se thin films were obtained by evaporation and electrodeposition techniques. ► We prepared Cu–Ga–Se films with good stoichiometry using evaporation and electrodeposition techniques. ► Anneal processes with Se improve the morphology and y optoelectronic properties of Cu–Ga–Se films.