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 CuGaSe ₂ phase is formed when the thickness of Ga is 0.25μm, however at 0.5μm and 1.0μm Ga the formation of CuGa ₃Se ₅ and CuGa ₅Se ₈ phases is observed respectively. Band gap values were obtained using photocurrent spectroscopy.