  Cu2O nanorods have been deposited on soda-lime glass (SLG) substrates by the
modified SILAR technique by varying the concentration of NaCl electrolyte into
the precursor complex solution. The structural, electrical, and optical
properties of synthesized Cu2O nanorod films have been studied by a variety of
characterization tools. Structural analyses by XRD confirmed the
polycrystalline Cu2O phase with (111) preferential growth. Raman scattering
spectroscopic measurements conducted at room temperature also showed
characteristic peaks of the pure Cu2O phase. The surface resistivity of the
Cu2O nanorod films decreased from 15,142 to 685 Ohm.cm with the addition of
NaCl from 0 to 4 mmol, and then exhibited an opposite trend with further
addition of NaCl. The optical bandgap of the synthesized Cu2O nanorod films was
observed as 1.88 - 2.36 eV, while the temperature-dependent activation energies
of the Cu2O films were measured as about 0.14 - 0.21 eV. SEM morphologies
demonstrated Cu2O nanorod as well as closely packed spherical grains with the
alteration of NaCl concentration. The Cu2O phase of nanorods was found stable
up to 230 0C corroborating the optical bandgap results of the same. The film
fabricated in presence of 4 mmol of NaCl showed the lowest resistivity and
activation energy as well comparatively uniform nanorod morphology. Our studies
demonstrate that the nominal presence of NaCl electrolytes in the pre-cursor
solutions has a significant impact on the physical properties of Cu2O nanorod
films which could be beneficial in optoelectronic research.
