39 Inorganic luminescent pigments
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Gerhard Pfaff
Abstract
Inorganic luminescent pigments (luminescent materials, luminophores, phosphors) as synthetically generated crystalline compositions absorb energy followed by emission of light with lower energy, respectively, longer wavelengths. The light emission occurs often in the visible spectral range. External energy is necessary to enable luminescent materials to generate light. Luminescent pigments are divided into fluorescent and phosphorescent pigments. This classification goes back to different energy transitions. Emission based on allowed optical transitions, with decay times in the order of μs or faster is defined as fluorescence. Emission with longer decay times is called phosphorescence. The occurrence of fluorescence or phosphorescence as well as the decay time depend on structure and composition of a specific luminophore. There are four luminescence mechanisms discussed for inorganic luminescent materials: center luminescence, charge-transfer luminescence, donor-acceptor pair luminescence, and long-afterglow phosphorescence. The emission of luminescent light can have its origin in different excitation mechanisms such as optical excitation (UV radiation or even visible light), high-voltage or low-voltage electroluminescence and excitation with high energy particles (X-rays, γ-rays). Inorganic luminescent pigments are used mainly in fluorescent lamps, cathode-ray tubes, projection television tubes, plasma display panels, light-emitting diodes (LEDs) and for X-ray and γ-ray detection. The pigment particles are dispersed for the applications in specific binder systems. They are applied in form of thin layers and by means of luminophore/solvent suspensions, containing adhesive agents, on a substrate.
Abstract
Inorganic luminescent pigments (luminescent materials, luminophores, phosphors) as synthetically generated crystalline compositions absorb energy followed by emission of light with lower energy, respectively, longer wavelengths. The light emission occurs often in the visible spectral range. External energy is necessary to enable luminescent materials to generate light. Luminescent pigments are divided into fluorescent and phosphorescent pigments. This classification goes back to different energy transitions. Emission based on allowed optical transitions, with decay times in the order of μs or faster is defined as fluorescence. Emission with longer decay times is called phosphorescence. The occurrence of fluorescence or phosphorescence as well as the decay time depend on structure and composition of a specific luminophore. There are four luminescence mechanisms discussed for inorganic luminescent materials: center luminescence, charge-transfer luminescence, donor-acceptor pair luminescence, and long-afterglow phosphorescence. The emission of luminescent light can have its origin in different excitation mechanisms such as optical excitation (UV radiation or even visible light), high-voltage or low-voltage electroluminescence and excitation with high energy particles (X-rays, γ-rays). Inorganic luminescent pigments are used mainly in fluorescent lamps, cathode-ray tubes, projection television tubes, plasma display panels, light-emitting diodes (LEDs) and for X-ray and γ-ray detection. The pigment particles are dispersed for the applications in specific binder systems. They are applied in form of thin layers and by means of luminophore/solvent suspensions, containing adhesive agents, on a substrate.
Kapitel in diesem Buch
- Frontmatter I
- Preface V
- Contents VII
- List of contributors XV
- 23 Color measurement 407
- 24 Cyanine dyes 465
- 25 Diarylethene dyes 503
- 26 Diketopyrrolopyrrole (DPP) pigments 525
- 27 Dioxazine pigments 535
- 28 Disazo (Bishydrazone) condensation pigments 543
- 29 Disazo (Bishydrazone) pigments based on acetoacetanilides 555
- 30 Disazo (Bishydrazone) pigments based on pyrazolones 571
- 31 Dyes: quantum chemical calculation of electronic spectra 577
- 32 Effect pigments 605
- 33 Fluorescence and fluorescent dyes 611
- 34 Fulgide dyes 651
- 35 Hemicyanine dyes 671
- 36 Hemioxonol dyes 685
- 37 Historical pigments, dyes and binders 691
- 38 Indophenol and related dyes 749
- 39 Inorganic luminescent pigments 765
- 40 Iron blue pigments 777
- 41 Iron oxide pigments 783
- 42 Merocyanine dyes 799
- 43 Metal complex pigments 815
- 44 Metal effect pigments 829
- Index 849
Kapitel in diesem Buch
- Frontmatter I
- Preface V
- Contents VII
- List of contributors XV
- 23 Color measurement 407
- 24 Cyanine dyes 465
- 25 Diarylethene dyes 503
- 26 Diketopyrrolopyrrole (DPP) pigments 525
- 27 Dioxazine pigments 535
- 28 Disazo (Bishydrazone) condensation pigments 543
- 29 Disazo (Bishydrazone) pigments based on acetoacetanilides 555
- 30 Disazo (Bishydrazone) pigments based on pyrazolones 571
- 31 Dyes: quantum chemical calculation of electronic spectra 577
- 32 Effect pigments 605
- 33 Fluorescence and fluorescent dyes 611
- 34 Fulgide dyes 651
- 35 Hemicyanine dyes 671
- 36 Hemioxonol dyes 685
- 37 Historical pigments, dyes and binders 691
- 38 Indophenol and related dyes 749
- 39 Inorganic luminescent pigments 765
- 40 Iron blue pigments 777
- 41 Iron oxide pigments 783
- 42 Merocyanine dyes 799
- 43 Metal complex pigments 815
- 44 Metal effect pigments 829
- Index 849
