Formation of CIGS thin absorption layer by sequential sputtering of CuGa/In/CuGa precursor on Mo/SLG with post selenization

Precursor structures of CuGa/In/CuGa stacking layers were prepared on Mo/soda-lime glass by sequential sputtering using intermetallic CuGa and metal In targets, with post selenization by Se evaporation at substrate temperature 500 C. The selenized CIGS thin films were characterized by X-ray photo electron spectroscopy, X-ray diffraction, energy dispersive spectroscopy, Field emission scanning electron microscopy (FE-SEM), and Photoluminescence (PL). XPS survey spectra show that the constituent elements such as Cu, Ga, In, and Se appeared on the surface composition with corresponding photoelectron lines and a detailed study of the Se 3d signal in the CIGS absorption layer was discussed. The X-ray diffractograms of the CIGS films exhibited peaks revealing that the films are crystalline in nature with tetragonal chalcopyrite structure. FESEM images reveal that CIGS thin films yield granular nanostructure and a Mo back contact with a columnar structure. The CIGS thin films demonstrated intense near-band-edge PL and free-to-bound transitions were found and reported.