Band edges determination of CuInS2 thin films prepared by electrodeposition

A CuInS2 (CIS) semiconductor thin film was growth by electrodeposition on a stainless steel substrate. In order to improve the polycrystallinity the samples were annealed in a N2 atmosphere. The films were characterized by electrochemical techniques and X ray diffraction and their band gaps were determined by photocurrent spectroscopy. When the electrolytic bath has the same concentration [Cu2+] = [In3+] the resulting film was of the n-type, while for different concentrations of Cu and In ions the film was of the p-type. A depletion zone during capacitance–voltage measurements at 10 kHz frequency was seen over the voltage range used. Using C–V plots in the depletion zone, flat-band potentials and the energetic position of band edges were calculated.