4. γ-Al2O3:Ce3+Cu2+ as a phosphor material; DFT+U and experimental approach
Abstract
The γ-Al2O3 and Ce3+Cu2+-doped γ-Al2O3 powders have been synthesized by sol-gel method. Phases of the synthesized powders were characterized with X-ray diffraction. Morphological analysis and elemental composition of the samples were determined by scanning electron microscopy, high-resolution transmission electron microscopy and energy dispersive X-ray spectroscopy. Luminescence characterizations have been used to study the synthesized samples. Ab initio calculations by the use of local density approximation with the Hubbard U correlation were used to compute the structural, electronic and optical properties of γ-Al2O3 and Al2O3:Ce3+Cu2+. The results indicate that the particle size and morphology of the samples depend on the concentration of the dopants. In comparison with undoped γ-Al2O3 sample, the intensities of emission peaks at 430 and 458 nm of Ce3+Cu2+-doped γ-Al2O3 powders have been enhanced. This shows that, increasing Ce3+ and Cu2+ concentration causes an increase in the number of emitting ions which is expected in order to increase the number of applications of γ-Al2O3:Ce3+Cu2+ composite powders. The photoluminescence spectrum detected at λex = 253 nm shows a new peak located at 549 nm due to Cu2+ ions. This was confirmed computationally when the Ce_4f and Ce_5d states are found in the conduction band while the Cu_4p state was found at conduction band minimum and Cu_3d state at valence band maximum. This location of states showed there is no possible luminescence from the Ce3+ ions. The only possible luminescence was due to transition from Cu_4p to Cu_3d states.
Abstract
The γ-Al2O3 and Ce3+Cu2+-doped γ-Al2O3 powders have been synthesized by sol-gel method. Phases of the synthesized powders were characterized with X-ray diffraction. Morphological analysis and elemental composition of the samples were determined by scanning electron microscopy, high-resolution transmission electron microscopy and energy dispersive X-ray spectroscopy. Luminescence characterizations have been used to study the synthesized samples. Ab initio calculations by the use of local density approximation with the Hubbard U correlation were used to compute the structural, electronic and optical properties of γ-Al2O3 and Al2O3:Ce3+Cu2+. The results indicate that the particle size and morphology of the samples depend on the concentration of the dopants. In comparison with undoped γ-Al2O3 sample, the intensities of emission peaks at 430 and 458 nm of Ce3+Cu2+-doped γ-Al2O3 powders have been enhanced. This shows that, increasing Ce3+ and Cu2+ concentration causes an increase in the number of emitting ions which is expected in order to increase the number of applications of γ-Al2O3:Ce3+Cu2+ composite powders. The photoluminescence spectrum detected at λex = 253 nm shows a new peak located at 549 nm due to Cu2+ ions. This was confirmed computationally when the Ce_4f and Ce_5d states are found in the conduction band while the Cu_4p state was found at conduction band minimum and Cu_3d state at valence band maximum. This location of states showed there is no possible luminescence from the Ce3+ ions. The only possible luminescence was due to transition from Cu_4p to Cu_3d states.
Chapters in this book
- Frontmatter I
- Preface V
- Contents VII
- List of Contributing authors XIII
- 1. Optical properties of monolayer BeC under an external electric field: A DFT approach 1
- 2. Theoretical investigation of the derivatives of favipiravir (T-705) as potential drugs for Ebola virus 19
- 3. Potential thermally activated delayed fluorescence properties of a series of 2,3-dicyanopyrazine based compounds 33
- 4. γ-Al2O3:Ce3+Cu2+ as a phosphor material; DFT+U and experimental approach 49
- 5. A DFT perspective analysis of optical properties of defected germanene mono-layer 65
- 6. DFT studies on storage and adsorption capacities of gases on MOFs 83
- 7. Metastability of the boron-vacancy complex in silicon: Insights from hybrid functional calculations 113
- 8. Molecular structure and vibrational spectra of 2-(4-bromophenyl)-3-(4-hydroxyphenyl) 1,3-thiazolidin-4-one and its selenium analogue: Insights using HF and DFT methods 123
- 9. Complexes between core-modified porphyrins ZnP(X)4 (X = P and S) and small semiconductor nanoparticle Zn6S6: are they possible? 135
- 10. DFT computations on vibrational spectra: Scaling procedures to improve the wavenumbers 147
- 11. Substituent effects on linear and nonlinear optical properties of fluorescent (E)-2-(4-halophenyl)-7- arlstyrylimidazo[1,2-A] pyridine: spectroscopic and computational methods 193
- Index 229
Chapters in this book
- Frontmatter I
- Preface V
- Contents VII
- List of Contributing authors XIII
- 1. Optical properties of monolayer BeC under an external electric field: A DFT approach 1
- 2. Theoretical investigation of the derivatives of favipiravir (T-705) as potential drugs for Ebola virus 19
- 3. Potential thermally activated delayed fluorescence properties of a series of 2,3-dicyanopyrazine based compounds 33
- 4. γ-Al2O3:Ce3+Cu2+ as a phosphor material; DFT+U and experimental approach 49
- 5. A DFT perspective analysis of optical properties of defected germanene mono-layer 65
- 6. DFT studies on storage and adsorption capacities of gases on MOFs 83
- 7. Metastability of the boron-vacancy complex in silicon: Insights from hybrid functional calculations 113
- 8. Molecular structure and vibrational spectra of 2-(4-bromophenyl)-3-(4-hydroxyphenyl) 1,3-thiazolidin-4-one and its selenium analogue: Insights using HF and DFT methods 123
- 9. Complexes between core-modified porphyrins ZnP(X)4 (X = P and S) and small semiconductor nanoparticle Zn6S6: are they possible? 135
- 10. DFT computations on vibrational spectra: Scaling procedures to improve the wavenumbers 147
- 11. Substituent effects on linear and nonlinear optical properties of fluorescent (E)-2-(4-halophenyl)-7- arlstyrylimidazo[1,2-A] pyridine: spectroscopic and computational methods 193
- Index 229
