Facile synthesis of Cu2O nanorods in the presence of NaCl by SILAR method and its characterizations

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 pre-cursor 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
Ω.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℃ 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.