Abstract
The effect of the annealing temperature on the CuInSe2 (CIS) electrodeposed films on FTO substrates has been investigated. Followed by different annealing, in vacuum and for different temperatures, X-ray diffraction has proved that the CuInSe2 films have chalcopyrite structure oriented along the (112) direction with good crystallinity at 400 degree C. From the evolution of the full width at half maximum (FWHM) of the (112) peak, we have estimated the grain size versus the annealing temperature. The results show that the grain size increases from 0.45 to 0.75 mu m with the annealing temperature. The morphological, optical and electrical properties of the CIS films have been investigated respectively, by the scanning electron microscopy (SEM), UV-vis spectroscopy and I-V characteristics. The band gaps of the CIS films also shows an evolution when the temperature is varied. In fact the band gap decreases from 1.24eV at 250 degree C to 0.98eV at 450 degree C. The electrical characterization of the junction Al/CIS/FTO shows an interesting Schottky rectifying behavior.