Control of the structure and photoelectrical properties of Cu(InGa)Se2 film by Ga deposition potential in two-step electrodeposition

In present work, a simple two-step electrodeposition method (first CuIn then Ga) was used to prepare the Cu-In-Ga precursor. The as-deposited films were selenized in nitrogen atmosphere at 550 degrees C for 40min. The effect of Ga deposition potential on the structural, morphological, optical and electrical properties were investigated by means of X-ray diffraction, Raman spectra, scanning electron microscopy, UV-visible Spectroscopy and photo-electrochemical measurement, respectively. XRD results show that prepared Cu(InGa)Se-2 films have a tetragonal chalcopyrite CIS with preferential orientation along the (112) orientation. And the size of grain and the band gap were various with the increase of the Ga deposited potential, resulting in the effective control of photo-current intensity of Cu(InGa)Se-2. The Mott-Schottky plots confirmed all the films exhibited a good p-type semiconductor characteristic.