Structural characterization and thermally stimulated discharge conductivity (TSDC) study in polymer thin films

Sangawar, Vijaya S.; Dhokne, Ragini; Ubale, A.U.; Chikhalikar, P. S.; Meshram, Suresh

doi:10.1007/s12034-007-0029-2

Cited by 36 publications

(12 citation statements)

References 7 publications

(6 reference statements)

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“…8(a and b) shows the plots of Log (r) and Log (f) at a frequency range of 42 Hz to 1 MHz with a temperature range of 303 K to 433 K. The rise of electrical conductivity with an increase of frequency is common for semiconductor and polymeric materials. This is might be due to the fact that, as the dopant concentration is increased, the dopant molecules start bridging the gap separating the two localized states and lowering the potential barrier between them, thereby facilitating the transfer of charge carrier between two localized states [33]. The behavior of the curves clearly indicates an increase in the conductivity with increasing of the temperature.…”

Section: Ac Electrical Conductivitymentioning

confidence: 98%

Raman, morphology and electrical behavior of nanocomposites based on PEO/PVDF with multi-walled carbon nanotubes

Elashmawi

Gaabour²

2015

Results in Physics

125

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a b s t r a c tIn this work, FT-IR, Raman, TEM spectroscopy and AC conductivity were used to study and characterize of PEO/PVDF blend incorporated with low content of multi-walled carbon nanotubes (MWCNTs). Main characteristics of IR and Raman bands for the two polymers and MWCNTs were observed. The shift of G, D and G 00 bands of MWCNTs occurred. All results showed that MWNTs-COOH were covalently linked with the blend through OH and C-C bonds. TEM images illustrated that MWNTs were well dispersed into polymeric matrices and wrapped with PEO/PVDF chains. The temperature dependent conductivity measurements of nanocomposites were studied. The addition of MWCNTs increases and enhances the conductivity attributed to charge carrier build up and increases in segmental mobility of polymeric chains. Molecules in the loaded samples begin to bridge the gap which separates them by lowering potential barriers and the localized state between them. Values of both e 0 and e 00 are high at lower frequency and decrease with an increase of frequencies due to polarization effects.

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Section: Ac Electrical Conductivitymentioning

confidence: 98%

Raman, morphology and electrical behavior of nanocomposites based on PEO/PVDF with multi-walled carbon nanotubes

Elashmawi

Gaabour²

2015

Results in Physics

125

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“…In case of solids, the absorption of photons could also occur for photon energies lesser than or equal to the energy gap, hν ≤ E opt due to the presence of tail states in the forbidden gap. The absorption coefficient at the photon energy below the optical gap (tail absorption) depends exponentially on the photon energy and obeys the Urbach relation 36 given as…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Opto-Electrical Characteristics of Poly(vinyl alcohol)/Cesium Zincate Nanodielectrics

Subramani

Siddaramaiah

2015

J. Phys. Chem. C

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Polymer nanocomposites for electro-optics are known to offer novel material morphologies and unique device geometries, thereby enhancing the device performance. In this study, we report the successful fabrication of one such blue-green fluorescent poly(vinyl alcohol) (PVA)/cesium zincate (Cs 2 ZnO 2 ) nanocomposite by solution intercalation technique. The optoelectronic properties of prepared films were probed with the intent to establish the effect of nanointegrates on optical and electrical characteristics of particle stabilizing PVA. The optical absorbance studies revealed the UV absorbent nature of PVA/Cs 2 ZnO 2 films exhibiting a steep UV absorption coupled with high visible transmission. The optical parameters of nanocomposite films, including absorption/extinction coefficients, optical band gap, complex refractive index (RI), and dielectric functions besides optical conductivity were evaluated, which supports the dopantdependent optical properties of PVA with a scope for band gap engineering. The dispersion and functionalization of nanofillers were characterized by FESEM. The integrated fillers induced a broad blue−green luminescence (2.88−2.58 eV) in the emission spectrum of PVA. The structural aspects were probed by FTIR studies, while charge transport properties were valued by dielectric studies. The dielectric properties (dielectric storage and dielectric loss), AC conductivity, and charge dissipation were found to increase with nanofiller content and decrease with frequency. ■ INTRODUCTIONPolymer nanocomposites are of particular interest in photonics and optoelectronics, owing to their excellent ability to harness unique material properties arising from the synergistic combination of opto-electrical effectiveness of the nanoinclusions, alongside admirable processability of the polymer systems. The unearthing of compounds with interesting material properties often opens up novel research pathways, eventually leading to new technology. A proper understanding of unearthed properties and their filler-dependent tuning may lead to hybrid devices with advanced properties. This is the central theme in smart material technology, which involves efforts to tune the material properties according to specific application requirements. This involves the simultaneous and perhaps synergistic tailoring of various properties, which can be nontrivial. Polymer nanocomposite technology is one such area, which utilizes the unique material properties arising from sizedependent material properties to design/develop and fabricate materials with unique physicochemical properties for specified applications. In recent years, polymer-encapsulated transparent semiconducting inorganic nanofillers have attracted a great deal of scientific and technological interest as advanced technological materials, especially in the field of photonics and optoelectronics. 1−5 Polymer nanocomposites are also extensively employed in applications related to optical storage systems owing to their exceptionally high thermal stability and filler-depend...

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“…The obtained data revealed that the optical energy band gap decrease significantly with increasing nano Cr 2 S 3 concentration, which may be explained on the basis of the fact that the incorporation of small amounts of dopant forms charge transfer complexes in the host matrix (Abdullah, et al 2013). These charge transfer complexes increase the electrical conductivity by providing additional charges, this result in a decrease of the optical energy band gap, by facilitating the transfer of charge carrier between the localized states (Abdelrazek, et al, 2013;Sangawar, et al, 2007). The width of the localized tail states in the forbidden gap (Urbach tail), is an indicator of the defect levels in the forbidden band gap (El-Khodary, 2010).The absorption coefficients just below the fundamental gap can be used to calculate the Urbach energy using following relations (Urbach 1953):…”

Section: Resultsmentioning

confidence: 99%

Optical Properties of the Synthesized Cr2S3 Nanoparticles Embedded in Polyvinyl Alcohol

Abdullah

Tahir

Saber

2015

ARO

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Polyvinyl alcohol (PVA) based nanocomposite, with different concentrations of chromium sulfide Cr 2 S 3 nanoparticles, were prepared by reduction of Cr(NO 3 ) 3 and Na 2 S in an aqueous PVA solution, using the chemical reduction rote, and casting technique. Effect of Cr 2 S 3 nanoparticles on optical parameters such as absorbance, absorption coefficient, refractive index, and extinction coefficient have been investigated using UV-Visible spectroscopy. The study reveals that all these parameters are affected by the Cr 2 S 3 nanoparticles concentration. The study has been also extended to investigate the changes in the optical band gap energies, the band tail width for the samples using Tauc and Urbach relations respectively. The optical energy band gap reduced from (6.17 eV) for pure PVA to (4.14 eV) for 0.04M Cr 2 S 3 ; while the Urbach tail increased from (0.216 eV) for pure PVA to (0.523 eV) for 0.04M Cr 2 S 3 . The significant change of the optical properties of PVA with embedded Cr 2 S 3 nanoparticles suggested their applicability in optical devices.Index Terms-Cr 2 S 3 nanoparticles, filler effect, optical properties, polymer nanocomposite, solution cast technique.

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Structural characterization and thermally stimulated discharge conductivity (TSDC) study in polymer thin films

Cited by 36 publications

References 7 publications

Raman, morphology and electrical behavior of nanocomposites based on PEO/PVDF with multi-walled carbon nanotubes

Raman, morphology and electrical behavior of nanocomposites based on PEO/PVDF with multi-walled carbon nanotubes

Opto-Electrical Characteristics of Poly(vinyl alcohol)/Cesium Zincate Nanodielectrics

Optical Properties of the Synthesized Cr2S3 Nanoparticles Embedded in Polyvinyl Alcohol

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