Samples of ZnO/TiO
2
bilayer films with various layer thickness were fabricated by atomic layer
deposition (ALD). The X-ray diffraction (XRD) patterns revealed the absence of sharp peaks and
confirms the amorphous nature of the samples under study. The absorption spectra of ZnO/TiO
for the three samples were obtained in view of incident wavelength range (350–700 nm). The
absorption spectra were used to determine the optical energy band gap. The experimental results
show that the direct optical band gap (E
) grown on glass substrate was obviously affected by the
increase of the number of ZnO/TiO
2
g
bilayers and found to decrease from (3.45 to 2.96 eV). The
transition power factor (P
) for the three samples was applied to confirm the direct optical
transition. A suitable relationship between the linear refractive index (n
F
) and the optical energy
band gap (E
g
0
) determined from the experimental and theoretical data was proposed for providing
good basis for predication the metallization and polarizability criterion and other related parameters,
such
as
optical
dielectric
constant
and
electrical
susceptibility.
The
deep
analysis
of
the
studied
properties,
based
on
the
variation
of
the
number
of
the
bilayer
of
ZnO/TiO
, makes the
incorporation of these two materials promising candidates in various optoelectronic applications
and solar cell devices.
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