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Full-Text Articles in Physical Sciences and Mathematics
Gamma Irradiation Effect On The Optical Properties And Refractive Index Dispersion Of Dye Doped Polystyrene Films, Tariq J. Alwan
Gamma Irradiation Effect On The Optical Properties And Refractive Index Dispersion Of Dye Doped Polystyrene Films, Tariq J. Alwan
Turkish Journal of Physics
In this work, we have studied the effect of the gamma irradiation on the optical properties and optical constants of Polystyrene doped by methylene blue (mb) with thickness in the range 0.11 + 5 mm. The samples have been investigated via transmittance and reflectance spectra, and characterized in the wavelength range 300-900 nm. The optical band gap E_g was determined while the optical absorption spectra showed that the absorption mechanism is an indirect allowed transition, which found that optical energy gap E_g decreases after irradiation. The optical constants (refractive index, extinction coefficient, and real and imaginary parts of the dielectric …
The Composition Dependence Of The Optical Band Gap In Ge Doped Se-Te Glassy Alloy, Mainika Kapoor, Nagesh Thakur
The Composition Dependence Of The Optical Band Gap In Ge Doped Se-Te Glassy Alloy, Mainika Kapoor, Nagesh Thakur
Turkish Journal of Physics
Bulk glasses with the chemical composition (Se_{80}Te_{20})_{100-x}Ge_x (x = 0, 2, 4, 6) have been prepared from high purity constituent elements. Fragments of the bulk glasses are used to deposit thin films by vacuum thermal evaporation and compositional dependence of the optical and physical properties have been studied. It has been found that optical absorption is due to indirect transition and the optical band gap E_g increases with increasing Ge content in Se-Te glassy alloy. The relationship between the E_g and chemical composition is discussed in terms of cohesive energy and co-ordination number.