Effect of reduction potential and post-deposition annealing on the structural, compositional and optical properties of electrodeposited copper(I) sulfide thin films

In the present work it is reported on the deposition of cuprous sulfide (Cu 2 S) by the electrodeposition technique and its characterization followed by a heat treatment. Cu 2 S films were deposited using reduction potentials in a range of − 600 to − 555 mV (vs. SCE) with a deposition time of 1000 s. The annealing process was performed varying the atmosphere (inert or with sulfur) and temperature (250 and 350 °C). The properties of deposited Cu 2 S films were analyzed using UV–Vis spectroscopy, X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The deposited films had a hexagonal structure in the chalcocite phase and showed a band gap in the range of 1.61 and 1.8 eV. Characterization techniques demonstrated modifications in the properties of the material due to the presence or deficiency of sulfur in the films.