scholarly journals Europium-doped boro-bismuth-tellurite glasses for multicolor phosphor applications

2016 ◽  
Vol 94 (2) ◽  
pp. 188-191 ◽  
Author(s):  
K. Keshavamurthy ◽  
B. Eraiah
Keyword(s):  
Band Gap ◽  
Molar Volume ◽  
Urbach Energy ◽  
Glass System ◽  
Band Gaps ◽  
Tellurite Glasses ◽  
Melt Quenching ◽  
Yellow Orange ◽  
Quenching Method ◽  
Indirect Band Gap

The glass system (50–x)B2O3–30Bi2O3–20TeO2–xEu2O3 (x = 0, 0.1, 0.5, 1.0, 1.5, and 2.0 mol%) having been prepared using the conventional melt quenching method, is investigated in terms of physical, optical, and luminescence properties. The density of these glasses is measured and the corresponding molar volume is also calculated. The (αhν)1/n versus hν graph was plotted and it is well fitted to both direct (n = 1/2) and indirect (n = 2) band gaps. The direct and indirect band gap values range from 2.57 to 2.94 eV and 1.74 to 2.58 eV, respectively. The Urbach energy of the glass system was calculated to have values ranging from 0.29 to 0.62 eV. Yellow, orange, and red emissions have been observed through photoluminescence (PL) spectroscopy excited at 464 nm and the obtained multicolor emissions have been demonstrated according to the Commission International de l’Eclairage de France 1931 standards. The results of PL studies indicated the possibility towards the development of multicolor phosphor applications.

scholarly journals Optical Properties of Erbium doped Molybdenum Tellurite Glasses

2016 ◽  
Vol 15 (1) ◽  
pp. 17-27
Author(s):  
B Eraiah
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Urbach Energy ◽  
Amorphous Semiconductors ◽  
Tellurite Glasses ◽  
Melt Quenching ◽  
Erbium Doped ◽  
Uv Visible ◽  
Quenching Method ◽  
Indirect Band Gap

The glasses with the composition of xEr 2 O 3 -5AgCl- 15MoO 3 -(80-x) TeO 2 (x = 0, 0.5 and 1 mol%, named as SMT0, SMT1 and SMT2, respectively) were synthesized using conventional melt quenching method and their optical properties were investigated through UV-Visible spectrophotometer. Density and molar volume values of the glass samples were estimated, their values were found in the range from 5.52 to 5.64 g/cm 3 and 27.737 to 28.689 cm 3 , respectively. The UV absorption spectra were recorded at room temperature in the wavelength range 200-1100nm. From the absorption edge data, it is found that both the direct and indirect type transitions may takeplace. The direct and indirect band gap values are ranging from 1.92 to 2.29 eV and 1.24 to 1.77 eV, respectively. Also, the Urbach energy (E tail ) values were determined and their values are ranging from 0.33 to 0.54 eV. These obtained E tail values are well matched with amorphous semiconductors (0.046 to 0.66 eV).

scholarly journals Optical Properties of Erbium Zinc Tellurite Glass System

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Sidek Hj. Abdul Aziz ◽  
R. El-Mallawany ◽  
Siti Shawaliza Badaron ◽  
Halimah Mohamed Kamari ◽  
Khamirul Amin Matori
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Molar Volume ◽  
Absorption Spectra ◽  
Wavelength Range ◽  
Room Temperature ◽  
Tellurite Glass ◽  
Tellurite Glasses ◽  
Melt Quenching ◽  
Quenching Method

Er3+-doped tellurite glasses with molar compositions ofxEr2O3-20ZnO-(80-x)TeO2(x=0, 1, 2, 3, and 4 mole%) (EZT) have been successfully synthesized by the melt-quenching method. Density and molar volume have been measured. UV-VIS absorption spectra in the wavelength range of 400–800 nm at room temperature has been measured. The band gap for every composition has been calculated. Photoluminescence spectroscopy in the wavelength range of 400–650 nm and at room temperature has been evaluated.

Optical Absorption of Erbium Doped Zinc Phosphate Glass Containing Fe3O4 Nanoparticles

2015 ◽  
Vol 1107 ◽  
pp. 420-425 ◽  
Author(s):  
Puzi Anigrahawati ◽  
M.R. Sahar ◽  
Md Supar Rohani ◽  
Sib Krishna Ghoshal
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Molar Volume ◽  
Urbach Energy ◽  
Phosphate Glasses ◽  
Zinc Phosphate Glass ◽  
Erbium Doped ◽  
Quenching Method ◽  
Average Size

Modifying the optical properties of rare earth doped phosphate glasses in a tunable fashion via the embedment of magnetic nanoparticles (NPs) is challenging for magneto-optic devices. Glasses with compositions (69-x)P2O5-30ZnO-1Er2O3-(x)Fe3O4, where x = 0 to 1.5 mol% are prepared by conventional melt quenching method. The Fe3O4NPs concentration dependent density, molar volume, refractive index and optical properties are determined. Density and molar volume shows strong correlation with structural alteration in the presence of NPs. The XRD spectra confirm the disordered nature of the glass and TEM micrograph display the presence of spherical NPs with average size ~26 nm. The optical band gap and Urbach energy calculated from the room temperature absorption spectra recorded in the range of 350-1700 nm reveal significant improvement. The density and refractive index increases and the molar volume decreases with the increase of Fe3O4contents. The energy band gap for direct and indirect transitions varies in the range of 4.47-3.64 eV and 4.27-3.53 eV, respectively. The Urbach energy increases from 0.15 to 0.19 eV as the NPs concentration increases from 0 to 1.5 mol%.

Effect of Samarium Ions on Physical and Optical Properties of Zinc Borotellurite Glass System

2021 ◽  
Vol 317 ◽  
pp. 100-108
Author(s):  
Siti Nasuha Mohd Rafien ◽  
Azman Kasim ◽  
Norihan Yahya ◽  
Azhan Hashim ◽  
Wan Aizuddin Wan Razali
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Molar Volume ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Glass System ◽  
X Ray Diffraction ◽  
Indirect Transition ◽  
Vis Spectroscopy ◽  
Amorphous Nature

Modifying the physical and optical properties of zinc borotellurite glasses by controlling rare earth (RE) doping is important in order to obtain high quality glass. In this study, Samarium (Sm3+) doped zinc borotellurite glasses were successfully fabricated by using conventional melt-quenching technique with chemical composition (where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%). The physical properties by mean of their density as well as molar volume were measured while the optical properties have been studied through UV-Vis spectroscopy in order to determine the optical band gap (Eopt) and Urbach energy (ΔΕ) of the glass system. Optical absorption spectra of the glass samples were recorded in the range 350 nm - 750 nm at room temperature. The amorphous nature of the glass was confirmed from X-ray diffraction techniques. The density and molar volume of the glass samples were found to vary with respect to Sm3+ ions content. The value of optical band gap, Eopt lies between 2.605 eV to 2.982 eV for the direct transition and 2.768 eV to 3.198 eV for the indirect transition respectively. Meanwhile, the Urbach energy, ΔE was observed in the range of 0.112 eV to 0.694 eV respectively. The physical and optical properties were found to be strongly affected by the varying concentration of Sm3+ ions. Some other results will be analysed and discussed in detail.

Optical Absorption of Er3+/Nd3+ Co-Doped Tellurite Glass

2012 ◽  
Vol 501 ◽  
pp. 96-100 ◽  
Author(s):  
S. Akmar Roslan ◽  
M. Rahim Sahar ◽  
Ramli Arifin ◽  
Sib Krishna Ghoshal ◽  
M. Supar Rohani ◽  
...  
Keyword(s):  
Tellurite Glass ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Tellurite Glasses ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
X Ray ◽  
Diffraction Patterns ◽  
Quenching Method ◽  
Co Doped

Tellurite glasses of varying Er3+/Nd3+ concentration were successfully prepared by melt-quenching method. The X-Ray diffraction pattern was determined by using Siemens Diffractometer D5000 while the optical properties were measured using Shimadzu 3101 pc UV-VIS NIR scanning spectrophotometer. It was found that the diffraction patterns of all samples showed glasses characteristics. The optical band gap, Eopt¬ increased proportionally with the content of Er¬2O3 but Urbach energy, ∆E decreased due to the increasing Er2O3 contents.

Luminescence Properties of Cerium Doped Iron Calcium Boroaluminate Glass

2017 ◽  
Vol 268 ◽  
pp. 72-76
Author(s):  
S. Akmar Roslan ◽  
Ramli Arifin ◽  
Sib Krishna Ghoshal
Keyword(s):  
Band Gap ◽  
Emission Spectra ◽  
Green Emission ◽  
Band Gap Energy ◽  
Glass System ◽  
Optical Measurements ◽  
Excitation Wavelength ◽  
Gap Energy ◽  
Quenching Method ◽  
Indirect Band Gap

Borate glass system of composition (100-x)B2O3-15Al2O3-20CaO-0.4Fe2O3-xCeO2 with x = 0, 0.25, 0.50, 0.75, and 1.0 mol% were prepared using conventional melt-quenching method. Optical measurements were carried out at room temperature to determine the Cerium (Ce3+) ions concentration dependent absorption and luminescence emission properties of such glass system. Optical energy band gap of the glass system were evaluated as a function of Ce3+ ions content. Indirect band gap energy was found to be lower than the direct band gap energy. Urbach energy was ranged between 0.12-0.17 eV. An increased broad absorption is observed in the UV region with increasing Ce3+ ions concentration. The emission spectra of the glass system recorded with 380 nm excitation wavelength revealed prominent cyan-green emission.

Optical Studies of Poly (N-Carbazole) (PVK) Blending with Polyvinylpyrrolidone (PVP) Using Tauc/Davis-Mott Model

2013 ◽  
Vol 652-654 ◽  
pp. 527-531 ◽  
Author(s):  
A.N. Alias ◽  
T.I. Tunku Kudin ◽  
Z.M. Zabidi ◽  
M.K. Harun ◽  
Ab Malik Marwan Ali ◽  
...  
Keyword(s):  
Band Gap ◽  
Urbach Energy ◽  
Quartz Substrate ◽  
Optical Studies ◽  
Direct Band Gap ◽  
Mott Model ◽  
Blended Polymer ◽  
Electronic Parameters ◽  
Direct Band ◽  
Indirect Band Gap

The optical absorption spectra of blended poly (N-carbazole) (PVK) with polyvinylpyrrolidone (PVP) in various compositions are investigated. A doctor blade technique was used to coat the blended polymer on a quartz substrate. The electronic parameters such as absorption edge (Ee), allowed direct band gap (Ed), allowed indirect band gap (Ei), Urbach edge (Eu) and steepness parameter (γ) were calculated using Tauc/Davis-Mott Model. The results reveal that the Ee, Ed and Ei increase with increasing of PVP ratio. There also have variation changing in Urbach energy and steepness parameter.

Structural Studies of Lead Sodium Borate Glasses

2010 ◽  
Vol 93-94 ◽  
pp. 439-442
Author(s):  
Pruittipol Limkitjaroenporn ◽  
Jakrapong Kaewkhao ◽  
Suparat Tuscharoen ◽  
Pichet Limsuwan ◽  
Weerapong Chewpraditkul
Keyword(s):  
Molar Volume ◽  
Glass Network ◽  
Sodium Borate ◽  
Borate Glasses ◽  
Structural Studies ◽  
Melt Quenching ◽  
Network Modifier ◽  
Ir Analysis ◽  
Quenching Method ◽  
Glass Compositions

Glass compositions xPbO : 20Na2O : (80-x)B2O3 (x = 5,10,15,20,25,30,35,40,45,50 and 55 %mol) have been prepared using melt-quenching method. The density and molar volume of these glass samples have been found to be compositional dependent. The results indicate that PbO acts on the glass structures were different between the range 0≤ x ≤ 20 %mol and beyond x = 20 %mol (with inflection at x = 20 %mol). These due to the PbO can enter the glass network both as a network modifier and also as a network former. This role depends on the type of bond between lead and oxide. These results are interpreted in term of IR analysis.

Optical Properties of Silica Borotellurite Glass Doped with Manganese Oxide

2017 ◽  
Vol 268 ◽  
pp. 18-22 ◽  
Author(s):  
I. Zaitizila ◽  
Mohamed Kamari Halimah ◽  
Farah Diana Mohammad ◽  
Mohd Shah Nurisya
Keyword(s):  
Optical Properties ◽  
Manganese Oxide ◽  
Band Gap ◽  
Diffraction Pattern ◽  
Optical Band Gap ◽  
Urbach Energy ◽  
Molar Fraction ◽  
Chemical Formula ◽  
Melt Quenching ◽  
Amorphous Nature

Silica borotellurite glasses doped with manganese oxide with chemical formula {[(TeO2)0.7(B2O3)0.3­]0.8[SiO2]0.2}1-x{MnO2}x (where x = 0.0, 0.01, 0.02, 0.03, 0.04 and 0.05 molar fraction) were fabricated. Silica were extracted from the burning process of rice husk. Glass samples were prepared by using the melt-quenching technique. The FTIR spectra showed that the addition of MnO₂ contributed to the transformation of TeO4 to TeO3. The diffraction pattern of XRD showed a broad hump which indicates the amorphous nature of the samples. The result for both optical band gap and Urbach energy showed decreasing trend as the concentration of manganese increased.

Study on Physical and Photoluminescence Properties of Er3+Doped Zinc Barium Tellurite Glasses

2017 ◽  
Vol 728 ◽  
pp. 155-159 ◽  
Author(s):  
Patarawagee Yasaka ◽  
Yotsakit Ruangtaweep ◽  
Jakrapong Kaewkhao
Keyword(s):  
Molar Volume ◽  
Ground State ◽  
Atmospheric Pressure ◽  
Tellurite Glasses ◽  
Photoluminescence Spectra ◽  
Photoluminescence Properties ◽  
Melt Quenching ◽  
Absorption Bands ◽  
Volume Absorption ◽  
Doped Zno

Er3+-doped ZnO – BaO – TeO2 glasses with the formula (80-x)TeO2–15ZnO–5BaO–xEr2O3 were fabricated using melt quenching technique. The 5 glass samples with different concentrations of Er2O3 were prepared under atmospheric pressure. The samples were investigated on their properties: density, molar volume, absorption spectra and photoluminescence. Density was increased with an increase in Er3+ content. The molar volume trend is in the opposite way to that of the density. The absorption bands are assigned as absorptions from the 4I15/2 ground state to the 4F7/2, 2H11/2, 4S3/2, 4F9/2, 4I9/2, 4I11/2 and 4I13/2 levels. All absorption bands are increase with increasing content of Er3+. The photoluminescence spectra were measured with 980 nm light pumped by flash lamp. The spectra trends to increase with increasing concentration of the dopant.

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