Investigation of optical energy band gap of transition metal oxide/polystyrene nanocomposite foils

Author(s):  
Monika Barala ◽  
Bulkesh Siwach ◽  
Reetu Sangwan ◽  
Kavita Yadav ◽  
Devendra Mohan ◽  
...  
2015 ◽  
Vol 1107 ◽  
pp. 460-465
Author(s):  
M.Y. Nurulhuda ◽  
M.R. Sahar

A series of tellurite glass based on composition (89.6-x)TeO2-10MgO-xSm2O3-0.4AgCl where 0.2x1.0 have successfully been prepared by melt-quenching technique. The optical behaviour has been examined as a function of Sm2O3 content by using UV-Visible Spectroscopy in the range of 200-900 nm. The absorption studies revealed that the indirect and direct optical energy band gap is in the range of 2.81-3.11 eV and 3.16-3.45 eV, respectively. Meanwhile, Urbach energy, E is in between 0.18-0.24 eV. The increasing in samarium ion up to 0.4 mol% of Sm2O3 result in an increment of optical energy band gap, but gradually decreases beyond 0.4 mol%. All the results will be discussed with respect to Sm2O3 content.


2018 ◽  
Vol 183 ◽  
pp. 212-215 ◽  
Author(s):  
Gülşen Akın Evingür ◽  
Önder Pekcan

2003 ◽  
Vol 93 (1) ◽  
pp. 780-782 ◽  
Author(s):  
C. Rincón ◽  
S. M. Wasim ◽  
G. Marı́n ◽  
I. Molina

2000 ◽  
Vol 617 ◽  
Author(s):  
S. Boughaba ◽  
M. U. Islam

AbstractThin amorphous films of tantalum oxide were grown on borosilicate crown glass substrates by KrF excimer pulsed laser ablation of a Ta2O5 target, in an oxygen environment. The deposition was performed at a temperature of 250 or 400 °C, while the oxygen pressure was set in the range 5 to 30 mTorr. The optical properties of the tantalum oxide coatings, as evaluated by reflectance/transmittance spectrophotometry, were found to be dependent on the oxygen gas pressure. At a pressure of 5 mTorr, absorbing films were obtained, with extinction coefficients above 10−2 (at λ=633 nm), along with an optical energy band-gap as low as 0.7 eV. At a pressure of 10 mTorr and above, the coatings had refractive indices up to 2.25 (at λ=633 nm), extinction coefficients below 10−4 (for λ>390 nm), and an optical energy band-gap in the range 3.9 to 4.0 eV.


2017 ◽  
Author(s):  
Mohd Sabri Mohd Ghazali ◽  
Wan Rafizah Wan Abdullah ◽  
Azmi Zakaria ◽  
Muhamad Azman Zulkifli ◽  
Mohd Hafiz Mohd Zaid ◽  
...  

2014 ◽  
Vol 92 (10) ◽  
pp. 1154-1157
Author(s):  
G.V. Jagadeesha Gowda ◽  
B. Eraiah

Praseodymium doped silver–borate glasses having composition xPr6O11–(25 – x)Ag2O–75B2O3 (x = 0, 1, 2, 3, 4, 5) were prepared by conventional melt quenching method. The density, molar volume, and optical energy band gap of these glasses were measured. Optical absorption spectra of these glasses were recorded in the range 300–1000 nm at room temperature. The refractive index, molar refraction, and polarizability of oxide ion were calculated by using Lorentz–Lorentz relations. The oxide ion polarizabilities deduced from two different quantities, viz. refractive index and optical energy band gap, agree well compared with other glasses. The variation of the preceding optical parameters with respect to praseodymium concentration is explained.


2010 ◽  
Author(s):  
Dong-sheng Wang ◽  
Tao Yu ◽  
Di Wu ◽  
Ai-dong Li ◽  
An Hu ◽  
...  

2011 ◽  
Vol 110-116 ◽  
pp. 177-182 ◽  
Author(s):  
Omed Ghareb Abdullah ◽  
Dlear Rafiq Saber

Films of pure and doped Polyvinyl alcohol (PVA) with different concentration of Nickel Chloride (NiCl2) were prepared using the casting technique, in order to investigate the effect of NiCl2 additions on the optical properties of PVA host. The dispersion studies of pure PVA film and PVA films doped with NiCl2 were studied using complex refractive index in the wavelength range 190-1100 nm. The absorption spectral analysis showed that the optical energy band is due to the direct and indirect allowed optical transitions. The optical energy band gap Egopt of the films decreases with increasing NiCl2 contents, while the Urbach energy ∆Et called the width of localized states in the optical band gap decreases from 0.7414 to 0.1891 eV. The reductions of optical energy band gap were observed for all samples after annealing at temperatures 70oC for three hours.


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