scholarly journals Tl2S–In2S3–GeS2 Glass System as Novel Promising Materials for Photonics

2019 ◽  
Vol 20 (4) ◽  
pp. 416-422
Author(s):  
O.V. Tsisar ◽  
L.V. Piskach ◽  
O.V. Parasyuk ◽  
O.V. Zamurujeva ◽  
G.L. Myronchuk ◽  
...  
Keyword(s):  
Glass Transition ◽  
Optical Absorption ◽  
Band Gap ◽  
Structural Properties ◽  
Band Gap Energy ◽  
Optical Absorption Spectra ◽  
Characteristic Energy ◽  
Gap Energy ◽  
Glass Forming ◽  
Melting Temperatures

It was established that minimal content of the glass-forming component GeS2 is equal to 30 mol.% (by exploration the set of 23 different alloys with different composition). Correlation between structural properties, thermal parameters (glass transition, crystallization and melting temperatures) and optical absorption spectra along of the titled glasses system has been found. The temperatures, the band gap energy and the characteristic energy of vitreous alloys for the gastric system Tl2S‑In2S3‑GeS2 were investigated experimentally.

scholarly journals Optical absorption of divalent metal tungstates: Correlation between the band-gap energy and the cation ionic radius

2008 ◽  
Vol 83 (3) ◽  
pp. 37002 ◽  
Author(s):  
R. Lacomba-Perales ◽  
J. Ruiz-Fuertes ◽  
D. Errandonea ◽  
D. Martínez-García ◽  
A. Segura
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Ionic Radius ◽  
Band Gap Energy ◽  
Divalent Metal ◽  
Gap Energy ◽  
Metal Tungstates

Optical Absorption of Large Band-Gap SbxBi1-xI3 Alloys

2002 ◽  
Vol 744 ◽  
Author(s):  
C. Persson ◽  
R. Ahuja ◽  
J. Souza de Almeida ◽  
B. Johansson ◽  
C. Y. An ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Band Gap Energy ◽  
Full Potential ◽  
Generalized Gradient ◽  
Calculated Density ◽  
Augmented Plane Wave ◽  
Gap Energy ◽  
Generalized Gradient Approximation ◽  
Absorption Measurements

ABSTRACTThe optical properties of SbBiI3 alloys have been investigated experimentally by absorption measurements and theoretically by a full-potential augmented plane wave (FPLAPW) method within the generalized gradient approximation. The fundamental band-gap energy of these alloys changes from BiI3- to SbI3-like with increasing percentage of Sb content. The calculated band-gap energies as well as the optical absorption were found to be in a very good qualitatively agreement with the experimental results. We present calculated density-of-states as well as the dielectric functions for evaluation of future experiments.

scholarly journals Optical Characteristics of Some Binary and Ternary Phosphate Glasses

1995 ◽  
Vol 48 (5) ◽  
pp. 887 ◽  
Author(s):  
M Ashraf Chaudhry ◽  
Anwar Manzoor Rana ◽  
M Altaf ◽  
M Shakeel Bilal
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Glass Composition ◽  
Visible Region ◽  
Band Gap Energy ◽  
Phosphate Glasses ◽  
Optical Absorption Spectra ◽  
Gap Energy ◽  
Sharp Edges ◽  
Uv Visible

The optical absorption spectra of some binary and ternary phosphate glasses are studied in the UV-visible region by using a spectrophotometer. The observed absorbance versus wavelength curves do not show any sharp edges in these glasses. The optical band gap energies are found to depend significantly on glass composition. The optical band gap energy is found to increase with increasing ZnO content in binary and ternary glass systems.

EPR AND OPTICAL ABSORPTION STUDIES OF Mn2+ IONS IN ALKALI BOROTELLURITE GLASSES

2002 ◽  
Vol 16 (05n06) ◽  
pp. 143-159 ◽  
Author(s):  
P. GIRI PRAKASH ◽  
A. MURALI ◽  
J. L. RAO
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Optical Band Gap ◽  
Broad Band ◽  
Band Gap Energy ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Paramagnetic Resonance ◽  
Gap Energy ◽  
Splitting Parameter

Electron paramagnetic resonance (EPR) and optical absorption spectra of Mn2+ ions in alkali borotellurite glass systems have been studied. The EPR spectra of all the glass samples exhibit three resonance signals at g ≈ 2.0, g ≈ 3.3 and g ≈ 4.3. A six line hyperfine structure has also been observed at g ≈ 2.0. The concentration and temperature dependence of EPR signals were studied for Mn2+ ions in potassium borotellurite glass samples. The zero-field splitting parameter D has been calculated for different alkali borotellurite glass samples from the intensities of the allowed hyperfine lines. The paramagnetic susceptibility was calculated from the EPR data at various temperatures and the Curie constant was calculated from the 1/χ versus T graph. The optical absorption spectrum exhibits a single broad band near 498 nm and this has been attributed to the spin-allowed 5Eg → 5T2g transition of Mn3+ ions in octahedral symmetry. The optical band gap energy (E opt ) and Urbach energy (Δ E) were calculated from their ultraviolet edges. The optical band gap energy varies between 3.38 and 3.61 eV and increases from Li to K glasses.

scholarly journals Electrical Optical and Structural Properties of p-type Silicon

2015 ◽  
Vol 63 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Mehnaz Sharmin ◽  
Shamima Choudhury ◽  
Tahmina Begum
Keyword(s):  
Band Gap ◽  
Structural Properties ◽  
Optical Band Gap ◽  
Single Crystal Silicon ◽  
Diffraction Method ◽  
Band Gap Energy ◽  
Crystal Silicon ◽  
Gap Energy ◽  
Type Silicon ◽  
P Type

Electrical, optical and structural properties of p-type single crystal silicon were investigated in this work. Electrical conductivity of p-type silicon was measured in the temperature ranges 190 - 300 K. The acceptor ionization energy (?EA) was between 0.047 - 0.051 eV. Photoconductivity of the material was investigated by varying sample current, light intensity and temperature at a constant chopping frequency of 45.60 Hz. Absorption co-efficient (?) of the material was calculated from optical transmittance and reflectance measurements at room temperature (300 K) in the wavelength range of 300 -2500 nm. The direct optical band gap energy was found between 2.10 - 2.20 eV and the indirect optical band gap energy was found between 0.95 – 1.0 eV. The lattice parameter (a) was found to be 5.419Å from X-ray diffraction method (XRD). DOI: http://dx.doi.org/10.3329/dujs.v63i1.21766 Dhaka Univ. J. Sci. 63(1): 37-41, 2015 (January)

Pressure-dependent modifications in the optical and electronic properties of Fe(IO3)3: The role of Fe 3d and I 5p lone-pair electrons

2021 ◽  
Author(s):  
Akun Liang ◽  
Placida Rodríguez-Hernandez ◽  
Alfonso Munoz ◽  
Saqib Raman ◽  
Alfredo Segura ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Electronic Properties ◽  
Lone Pair ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Optical And Electronic Properties ◽  
Indirect Band Gap ◽  
Lone Pair Electrons

We have determined by means of optical-absorption experiments that Fe(IO3)3 is an indirect band-gap material with a band-gap energy of 2.1 eV. This makes this compound the iodate with the...

Modification of optical properties of PC-PBT/Cr2O3 and PC-PBT/CdS nanocomposites by gamma irradiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Color Difference ◽  
Band Gap Energy ◽  
Polybutylene Terephthalate ◽  
Γ Irradiation ◽  
Gap Energy ◽  
Vis Spectroscopy ◽  
Oxygen Atoms

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.

Stability Investigation in the Optical Properties of Thermally Evaporated Ge5Se95-x Znx Thin Films

2015 ◽  
Vol 7 (3) ◽  
pp. 1923-1930
Author(s):  
Austine Amukayia Mulama ◽  
Julius Mwakondo Mwabora ◽  
Andrew Odhiambo Oduor ◽  
Cosmas Mulwa Muiva ◽  
Boniface Muthoka ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Optical Band Gap ◽  
Thermal Evaporation ◽  
Optical Transition ◽  
Bulk Material ◽  
Band Gap Energy ◽  
Optical Absorbance ◽  
Gap Energy ◽  
Constituent Elements

 Selenium-based chalcogenides are useful in telecommunication devices like infrared optics and threshold switching devices. The investigated system of Ge5Se95-xZnx (0.0 ≤ x ≤ 4 at.%) has been prepared from high purity constituent elements. Thin films from the bulk material were deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as-deposited thin films using transmission spectra. The allowed optical transition was found to be indirect and the corresponding band gap energy determined. The variation of optical band gap energy with the average coordination number has also been investigated based on the chemical bonding between the constituents and the rigidity behaviour of the system’s network.

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