Formation of CuInSe2 thin films on flexible substrates by electrodeposition (ED) technique

This work reveals the formation of electrodeposition (ED) of CuInSe2 (CIS) film on flexible substrate. Ternary compounds were co-deposited on Au coated plastic substrate from an aqueous acidic solution containing 1 mM CuCl2, 5 mM InCl3 and 1 mM SeO2 adjusted to pH=1.65. It was found that the film stoichiometry improves when the growth solution consisted of 1 M triethanolamine (TEA) and 0.1 M Na-citrate. The optimal ED-CIS film was obtained after annealing at 150°C for 1 h in a nitrogen (N2) atmosphere. Optical absorption study showed that the energy gap of the annealed material is 1.18 eV. Good and reliable quality ED-CIS film was grown in this research with the potential use in fabricating flexible solar cells. This was supported by various analytical techniques, including energy dispersive spectroscopy (EDS), X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), ultraviolet/visible spectroscopy, Fourier transform infrared spectrometer (FTIR) and photoelectrochemical (PEC) characterization.