Anomalies of the refractive index and the optical energy gap of ferroelectric Pb1?x Ge x Te

1980 ◽  
Vol 40 (3) ◽  
pp. 193-198 ◽  
Author(s):  
W. Jantsch
2019 ◽  
Vol 13 (28) ◽  
pp. 162-169
Author(s):  
Jinan M. Hassan Jabir

Polyaniline polymer has been prepared by chemical oxidationpolymerization method in laboratory successfully. The PANI and(PVA+PVP) as a polymer blends in different percentage (30%, 50%,70%) from Polyaniline was prepared. The sample was studies asoptical properties by UV-vis spectrophotometer at (400-700) nm.The result of optical energy gap was 2.23 eV for pure (PVA+ PVP)and with additive was increasing with increasing PANI concentrationto become (2.49 for 30% to 2.52 for 70%) PANI. The goal of thisproject is prepare triple blend polymer and study the effect when addconductive polymer (Polyaniline) on the optical properties andcalculate optical constant as energy gap, refractive index, dielectricconstant and dielectric losses for (PVA+PVP) blends.


2019 ◽  
Vol 7 (1) ◽  
pp. 47
Author(s):  
Amera G. Baker

Polyaniline (PANI) salt in its pure and doped forms find extensive applications in making devices such as polymer light emitting diodes, photovoltaic, sensors, batteries, and super capacitors. PANI salt has been synthesized successfully through chemically oxidative polymerization of aniline in the presence of hydrochloric acid (HCl) and sulfuric acid (H2 SO4 ) using ammonium peroxydisulfate as an oxidizing agent. The absorption spectra of pure PANI salt and its doped state, in HCl and H2 SO4 media, have been studied in the wavelength range from 200 to 1100 nm using ultraviolet and visible near infrared spectrophotometer. Tauc’s formula, Lambert-Beer’s relation, and Fresnel’s formula were employed in the MATLAB program to calculate the optical energy gap, refractive index, and dielectric constant. Results showed that doping with HCl and H2 SO4 acidic mediums caused a reduction in the direct energy gap of the pure PANI from 2.69eV to 2.42 eV and 2.54 eV, respectively. The reduction in optical energy gap is associated with the increase in refractive index. The refractive index (2.92) has a higher value of PANI doped with HCl. Higher refractive index values are for better-structured films.


2006 ◽  
Vol 3 (1) ◽  
pp. 56-61
Author(s):  
Baghdad Science Journal

In this research study the effect of fish on the properties optical films thickness 1200-1800 and calculated energy gap Basra direct transport permitted and forbidden to membranes and urged decreasing values ??of Optical Energy Gap increase fish included accounts optical also calculate the constants visual as factories winding down and the refractive index and reflectivity membranes also by real part and imaginarythe dielectric constant


2013 ◽  
Vol 724-725 ◽  
pp. 176-179
Author(s):  
T. Zhang ◽  
H. Wang ◽  
Z.Y. Zhong ◽  
C.Y. Yang ◽  
Jin Hou

Transparent conducting gallium-titanium codoped zinc oxide thin films were grown onto glass substrates with magnetron sputtering technique in ambient argon gas, and the influence of argon pressure on optical properties of the films were investigated. The refractive indexes of the films were calculated. It is found that the refractive index tends to increase with increasing the photon energy. Meanwhile, the dispersion behavior of the refractive index was analyzed in terms of the single-oscillator model and the oscillator parameters were obtained. Furthermore, the optical energy gaps were evaluated by single-oscillator model and Tauc’s relation, respectively. The values of optical energy gap estimated from single-oscillator model are in agreement with those determined from Tauc’s relation.


2001 ◽  
Vol 8 (3-4) ◽  
pp. 251-259 ◽  
Author(s):  
M. Kepinska ◽  
M. Nowak ◽  
Z. Kovalyuk ◽  
R. Murri

1994 ◽  
Vol 144 (2) ◽  
pp. 311-316 ◽  
Author(s):  
R. Cadenas ◽  
M. Quintero ◽  
J. C. Woolley

2021 ◽  
Vol 16 (2) ◽  
pp. 281-287
Author(s):  
Alaa Y. Mahmoud

The effect of the volumetric ratio of the tris(8-hydroxyquinoline) aluminum (Alq3) on its blend with the N,N'-Di [(1-naphthyl)-N,N'-diphenyl]-(1,1'-biphenyl)-4,4'-diamine (NPD) (Alq3:NPD) is investigated and optimized for the UV photodetectors fabrication. The optical and structural properties of Alq3:NPD blend with different volumetric ratios 1:1, 2:1, and 3:1 is studied in the context of the absorbance, transmittance, optical energy gap and XRD patterns. Results show that the absorbance is increased by 11% at A = 260 nm with the increase in the volumetric ratio. In contrast, the optical energy bandgap that is extrapolated from the Tauc’s plot is decreased with the increase in the volumetric ratio, and the 2:1 ratio shows the lowest energy in the UV region. In terms of the XRD investigation, the 2:1 volumetric ratio shows the highest intensity for the crystallinity peak at 36.6°. The fabricated photodetector with a different volumetric ratio of the active layer Alq3:NPD blend shows the best performance with the ratio 2:1.


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