Characterization of Cu(In,Ga)Se2 thin films prepared via a sputtering route with a following selenization process

Cu(In,Ga)Se-2 films were prepared via a sputtering route with a following selenization process. In, Cu In, and Cu3Ga were observed in the precursor films. Selenization at 450 degrees C yielded monophasic Cu(In,Ga)Se-2 films. The diffraction angles of the (112) peaks shifted toward high angles, and a uniform morphology of the obtained films was observed with high-temperature selenization. The amount of gallium ions incorporated into indium ions increased with the temperature. The probable formation mechanism of the sputtering-derived Cu(In,Ga)Se-2 was proposed. Firstly, selenium species diffuse into the precursor films to form Cu(In,Ga)Se-2 and Cu2-xSe phases. Subsequently, the complete reaction of selenium with residual species leads to the formation reaction of single-phased Cu(In,Ga)Se-2. An efficiency of 8.34% was achieved for the fabricated solar cell. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.