CuInTe 2 thin films synthesis using one-step electrodeposition process: structural, optical, and electrical characterization

Polycrystalline CuInTe2 (CIT) films were grown onto ITO substrate by one-step electrodeposition technique using acidic aqueous solutions. In this study, the influence of the deposition time on CIT films properties was examined using six techniques, the X-ray diffraction, the scanning electron microscopy, the energy dispersive X-ray analysis, the optical transmittance, the Raman spectroscopy and the electrical properties measurements. The thickness of CuInTe2 films increases as the deposition time increases. The X-ray diffraction investigation of the films deposited during 5 and 10 min shows up only a tetragonal CuInTe2 chalcopyrite structure, with a preferred orientation along [112] direction. However, the films deposited during 15 and 20 min exhibits the CuInTe2 chalcopyrite structure as a main phase with In4Te3 as additional secondary phase. We have noticed a change in the preferred orientation axis of the prepared films as function of deposition time. The films show the direct allowed band gap and their energy band gap decreased from 1.06 to 0.99 eV as the deposition time increased from 5 to 20 min. Hall effect measurements show that the deposition time changes the conductivity type and films carrier concentration. The electrical conductivity is affected by the variation in the carrier mobility rather than by their concentration. The observed Raman modes in the films match well with those reported for single crystal CuInTe2 in the literature. All Raman spectra show the A1 mode at 127 cm−1 confirming the chalcopyrite crystalline quality of these films.