Microstructure And Compositional Distribution Of Selenized Cu(In,Ga) Se-2 Thin Film Utilizing Cu2in3, Cuga And Cu2se

A high-quality CIGS film with a selenization process needs to be developed for low-cost and large-scale production. In this study, we used Cu2In3, CuGa and Cu2Se sputter targets for the deposition of a precursor. The precursor deposited by sputtering was selenized in Se vapor. The precursor layer deposited by the co-sputtering of Cu2In3, CuGa and Cu2Se showed a uniform distribution of Cu, In, Ga, and Se throughout the layer with Cu, In, CuIn, CuGa and Cu2Se phases. After selenization at 550 degrees C for 30 min, the CIGS film showed a double-layer microstructure with a large-grained top layer and a small-grained bottom layer. In the AES depth profile, In was found to have accumulated near the surface while Cu had accumulated in the middle of the CIGS film. By adding a Cu-In-Ga interlayer between the co-sputtered precursor layer and the Mo film and adding a thin Cu2Se layer onto the co-sputtered precursor layer, large CIGS grains throughout the film were produced. However, the Cu accumulated in the middle of CIGS film in this case as well. By supplying In, Ga and Se to the CIGS film, a uniform distribution of Cu, In, Ga and Se was achieved in the middle of the CIGS film.