Electrical conduction mechanisms and dielectric constants of nanostructured methyl violet 2B thin films
Abstract The uniform thin films of methyl violet 2B,MV2B, with thicknesses ranged from 96 to 300 nm, ha been successfully prepared by spin coating technique.X-ray diffraction showed that the powder and pristine thin film of MV2B have amorphous structure. The amorphous pristine films become polymorphous nanocrystallites after
annealing at 433 K. The electrical properties of MV2B thin films have been studied. There are a number of operationalenvironments where the performance of MV2B thin filmsis likely to be affected significantly on their electricalproperties and dielectric constants such as the differences
of film thicknesses, temperatures and frequencies. It was
found that the DC conductivity of MV2B films increases
with increasing temperature. The extrinsic conduction
mechanism is operating in temperature range of
288–360 K with activation energy of 0.16 eV, and the
conduction in extrinsic region is explained via applying
Mott model for variable range hopping. The intrinsic
conduction mechanism is operating in temperatures
[360 K with activation energy of 0.91 eV. The conduction
in intrinsic region is explained by applying band to band
transitions theory. The AC electrical conductivity and dielectric
relaxation of MV2B thin films in the temperature
range 365–473 K and in frequency range 0.1–100 kHz has
been also studied. It has been shown that theoretical curves
generated from correlated barrier hopping, CBH, model
gives the best fitting with experimental results. Analysis of
these results proved that conduction occurs by phononassisted
hopping between localized states and it is performed
by bipolaron hopping mechanism. The temperature
and frequency dependence of both the real and imaginary
parts of dielectric constant have been investigated