EFFECT OF B2O3 ON PHYSICAL AND OPTICAL PROPERTIES OF ZINC PHOSPHATE GLASSES

2006 ◽  
Vol 20 (26) ◽  
pp. 1637-1643
Author(s):  
M. ALTAF ◽  
M. A. CHAUDHRY ◽  
M. TARIQ BHATTI
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Zinc Phosphate ◽  
Mass Density ◽  
Band Gap Energy ◽  
Phosphate Glasses ◽  
Exponential Dependence ◽  
Amorphous Nature ◽  
Sharp Edges ◽  
Band Tailing

Zinc-phosphate glasses with the addition of B 2 O 3 were prepared by using the melt quench technique. These glasses had a mol% composition of 30 ZnO -x B 2 O 3 - (70-x) P 2 O 5. The quantity x had values of 10–40 mol%. The mass density of these glasses was found to be in the range of 2.4912–3.0142 g/cm3. The oxygen packing density and molar volume were estimated to lie in the range 192.385–286.026 g-atom/liter and 46.78–31.46 cm3 respectively. The absorption spectra of these glasses were recorded in the range of 190 to 1100 nm. No sharp edges were found in the optical spectra, which confirms the amorphous nature of these glasses. The optical band gap energies were determined to be in the range of 2.40–3.00 eV. A decreasing behavior in optical band gap energy was seen due to the increasing concentration of B 2 O 3. The extent of band tailing was worked out from the Urbach plots, which showed an exponential dependence of absorption coefficients on photon energies.

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.

Absorption Properties of Er3+/Nd3+ Co-Doped Magnesium Phosphate Glasses

2017 ◽  
Vol 873 ◽  
pp. 14-19
Author(s):  
Mazlini Mazlan ◽  
Lili Widarti Zainuddin ◽  
Nur Sha’adah Zainuddin ◽  
Md Rahim Sahar
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Amorphous State ◽  
Band Gap Energy ◽  
Phosphate Glasses ◽  
Magnesium Phosphate ◽  
X Ray Diffraction ◽  
Amorphous Nature ◽  
Thermal Annealing Process ◽  
Co Doped

Magnesium phosphate glasses co-doped with Er3+/Nd3+ concentration were prepared using melt quenching technique and thermal annealing process was proposed to control any defects found in the glass samples. The physical and optical properties of the samples were investigated. The amorphous nature of the samples were confirmed using X-ray diffraction pattern. It shows that all samples are in amorphous state. The optical band gaps and Urbach energies were obtained from the optical absorption spectra. The studyshows that the optical band gap energy,Eopt isincreasingas the Nd2O3 content increased. Meanwhile, Urbach energies, ΔE decreased due to increase of Nd2O3 content. The results obtained from this study shows that the optical band gap, Eopt and the Urbach energy, ΔE are intherange of 3.95 –3.98 eV and 0.367 –0.437 eV respectively.

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.

scholarly journals Polymer Thermal Treatment Production of Cerium Doped Willemite Nanoparticles: An Analysis of Structure, Energy Band Gap and Luminescence Properties

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1118
Author(s):  
Ibrahim Mustapha Alibe ◽  
Khamirul Amin Matori ◽  
Mohd Hafiz Mohd Zaid ◽  
Salisu Nasir ◽  
Ali Mustapha Alibe ◽  
...  
Keyword(s):  
Solid State ◽  
Thermal Treatment ◽  
Band Gap ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Blue Emission ◽  
Green Emission ◽  
Band Gap Energy ◽  
Solid State Lighting ◽  
Gap Energy

The contemporary market needs for enhanced solid–state lighting devices has led to an increased demand for the production of willemite based phosphors using low-cost techniques. In this study, Ce3+ doped willemite nanoparticles were fabricated using polymer thermal treatment method. The special effects of the calcination temperatures and the dopant concentration on the structural and optical properties of the material were thoroughly studied. The XRD analysis of the samples treated at 900 °C revealed the development and or materialization of the willemite phase. The increase in the dopant concentration causes an expansion of the lattice owing to the replacement of larger Ce3+ ions for smaller Zn2+ ions. Based on the FESEM and TEM micrographs, the nanoparticles size increases with the increase in the cerium ions. The mean particles sizes were estimated to be 23.61 nm at 1 mol% to 34.02 nm at 5 mol% of the cerium dopant. The optical band gap energy of the doped samples formed at 900 °C decreased precisely by 0.21 eV (i.e., 5.21 to 5.00 eV). The PL analysis of the doped samples exhibits a strong emission at 400 nm which is ascribed to the transition of an electron from localized Ce2f state to the valence band of O2p. The energy level of the Ce3+ ions affects the willemite crystal lattice, thus causing a decrease in the intensity of the green emission at 530 nm and the blue emission at 485 nm. The wide optical band gap energy of the willemite produced is expected to pave the way for exciting innovations in solid–state lighting applications.

Optical band gap studies on xPb3O4–(1−x)P2O5 lead[(II,IV)] phosphate glasses

2002 ◽  
Vol 18 (4) ◽  
pp. 367-372 ◽  
Author(s):  
M Salagram ◽  
V Krishna Prasad ◽  
K Subrahmanyam
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Phosphate Glasses

The Optical Performance of Holmium Oxide Doped Tellurite Glass for Potential Optical Fiber

2021 ◽  
Vol 317 ◽  
pp. 95-99
Author(s):  
Muhammad Noorazlan Abd Azis ◽  
Halimah Mohamed Kamari ◽  
Suriani Abu Bakar ◽  
Azlina Yahya ◽  
Umar Saad Aliyu
Keyword(s):  
Refractive Index ◽  
Band Gap ◽  
Tellurite Glass ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Gap Energy ◽  
Xrd Method ◽  
Nonlinear Pattern

Borotellurite glass had been widely applied in the field of optical communications and devices. In this work, holmium oxides doped borotellurite glass had been successfully fabricated via conventional melt-quenched technique. The structural properties of holmium doped tellurite glass were found using x-ray diffraction (XRD) method. The nonexistence of sharp peaks in XRD pattern shows that the inclusion of holmium tellurite glass leads to the formation long range of disorderness. The optical properties of the glass system such as refractive index and optical band gap energy are investigated using UV-Vis spectrophotometer. The value of refractive index is found in nonlinear trend along with holmium oxides concentration. It is found that the refractive index is more than 2 at 0.01, 0.03 and 0.04 of holmium concentrations. The optical band gap energy was found in similar trend with refractive index which is in nonlinear pattern.

scholarly journals Effect of thickness on the optical properties of Gaas thin films

2013 ◽  
Vol 37 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Chitra Das ◽  
Jahanara Begum ◽  
Tahmina Begum ◽  
Shamima Choudhury
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Refractive Index ◽  
Band Gap ◽  
Optical Band Gap ◽  
Visible Region ◽  
Solar Spectrum ◽  
Band Gap Energy ◽  
Optical Parameters ◽  
Gap Energy

Effect of thickness on the optical and electrical properties of gallium arsenide (GaAs) thin films were studied. The films of different thicknesses were prepared by vacuum evaporation method (~10-4 Pa) on glass substrates at a substrate temperature of 323 K. The film thickness was measured in situ by a frequency shift of quartz crystal. The thicknesses were 250, 300 and 500 nm. Absorption spectrum of this thin film had been recorded using UV-VIS-NIR spectrophotometer in the photon wavelength range of 300 - 2500 nm. The values of some important optical parameters of the studied films (absorption coefficient, optical band gap energy and refractive index; extinction co-efficient and real and imaginary parts of dielectric constant) were determined using these spectra. Transmittance peak was observed in the visible region of the solar spectrum. Here transmittance showed better result when thicknesses were being increased. The optical band gap energy was decreased by the increase of thickness. The refractive index increased by increasing thickness while extinction co-efficient and real and imaginary part of dielectric constant decreased. DOI: http://dx.doi.org/10.3329/jbas.v37i1.15684 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 1, 83-91, 2013

scholarly journals Investigation of Band Tailing in Sputtered ZnO:Al Thin Films Regarding Structural Properties and Impurities

2014 ◽  
Vol 1699 ◽  
Author(s):  
Steffi Schönau ◽  
Florian Ruske ◽  
Sebastian Neubert ◽  
Bernd Rech
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Pure Aluminum ◽  
Growth Conditions ◽  
Band Gap Energy ◽  
Absorption Feature ◽  
Spectral Absorption ◽  
Spectral Absorption Coefficient ◽  
Additional Absorption ◽  
Band Tailing

ABSTRACTThin films of pure aluminum doped ZnO and with addition of nitrogen, oxygen and hydrogen have been prepared by magnetron sputtering. The spectral absorption coefficient close to the band gap energy has been determined by spectrophotometry and analyzed regarding band tailing and creation of defect bands. We found, that an improvement of Raman crystallinity under O2- rich growth conditions is not accompanied by a suppression of band tailing as expected. An additional absorption feature evolves for layers grown in N2 containing atmosphere. Doping with hydrogen attenuates sub-band gap absorption.

scholarly journals Influence of Mg2+-substitution on the optical band gap energy of Cr2−Mg O3 nanoparticles

2019 ◽  
Vol 13 ◽  
pp. 102106 ◽  
Author(s):  
Jarnail Singh ◽  
Vikram Verma ◽  
Rajesh Kumar ◽  
Ravi Kumar
Keyword(s):  
Band Gap ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Gap Energy
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