New Generation of Europium- and Terbium-Activated Phosphors From Syntheses to Applications

Preface
1. Phosphors and Luminescence
1.1 Luminescence Classification
1.1.1 Types of Excitation
1.1.2 Fluorescence and Phosphorescence
1.2 Luminescence Terminology
1.2.1 Quantum Numbers, Term Symbols and L-S Coupling
1.2.2 Selection Rules
1.3 Luminescent Materials
1.3.1 The Past and Present of Phosphors
1.3.2 Major Applications of Phosphors
1.4 Rare Earth Activation
1.4.1 Radiative and Non-radiative Transitions
1.4.2 Peculiarities of Eu and Tb Activation
2. Synthesis of Phoshors
2.1 General Requirements of Phosphors
2.2 Solid State Methods
2.2.1 Solid State Reaction
2.2.2.1 Preliminary powder preparation
2.2.2.2 Firing and calcinations
2.2.2.3 Post-treatment
2.2.2 Microwave Synthesis Method
2.3 Wet-Chemical Methods
2.3.1 Co-Precipitation
2.3.2 Sol–Gel Techniques
2.3.3 Hydrothermal
2.3.4 Solvothermal
2.3.5 Colloidochemical
2.3.6 Spray–Pyrolysis
2.3.7 Combustion Method
3.Phoshor Characterization
3.1 Morphology Analysis with Scanning Electron
Microscopy
3.1.1 Electron Beam Interaction with Solid Matter
3.1.2 SEM Images of Phosphors in Back-Scattered
Electrons
3.2 Cathodoluminescence Characterization
3.2.1 Monochromatic Cathodoluminescence
3.2.2 Panchromatic or Color Cathodoluminescence
3.2.3 Composite Cathodoluminescent and
Back-Scattering Electron Contrast in SEM
3.3 Microanalysis
3.3.1 Electron Probe Micro-Analyzer
3.3.2 Energy-Dispersive X-Ray Spectroscopy
3.3.3 Wavelength-Dispersive X-Ray Spectroscopy
3.3.4 Example of Microanalysis Application
3.4 Particle Size Analysis
3.4.1 Methods of Particle Analysis
3.4.2 Laser Diffraction
3.4.3 Cumulative and Density Distribution
3.5 X-Ray Diffraction Measurements
3.5.1 X-Ray Generation and Properties
3.5.2 Lattice Planes and Bragg’s Law
3.5.3 Powder Diffraction
3.5.4 Example of XRD Application
3.6 Spectroscopic Methods in Structural, Morphology
and Luminescence Characterization
3.6.Spectroscopy Classification
3.6.2 Photoluminescence Spectroscopy
3.6.2.1 Photoluminescence excitation
spectroscopy
3.6.2.2 Measurements in the vacuum-ultraviolet
region
3.6.3 X-Ray Generated Luminescence
3.6.4 Cathodoluminescence Spectroscopy
3.6.5 Fourier Transform Infrared Spectroscopy
3.6.6 Raman Spectroscopy
3.6.7 Terahertz Spectroscopy
3.7 Computational Materials Science
3.7.1 Ab initio Calculations
3.7.2 Monte Carlo Calculations
3.7.3 Hartree–Fock Algorithm
3.7.4 Density Functional Theory
4. Phosphors for Different Applications
4.1 Europium and Terbium Activated CaWO4
4.1.1 Introductory Remarks
4.1.2 Phosphor Preparation
4.1.3 Luminescence of Eu3+ and Tb3+ Activated
CaWO4 Phosphors
4.1.4 Analysis of Optical Lines
4.1.5 Polarization Selection Rules
4.1.6 Ab initio Calculations
4.1.7 Concluding Remarks
4.2 RE3+ Activated Y(Ta,Nb)O4-Based Phosphors
4.2.1 Introductory Remarks
4.2.2 Self-Activated Y(Ta,Nb)O4 Phosphors
4.2.3 Terbium Activated Y(Ta,Nb)O4 Phosphors
4.2.3.1 Effect of flux materials
4.2.3.2Effect of flux concentration
4.2.3.3 Effect of terbium concentration
4.2.3.4 Effect of niobium addition
4.2.4 Europium Activated Y(Ta,Nb)O4 Phosphors
4.2.4.1 Photoluminescence properties
4.2.4.2 Crystalline structure
4.2.4.3 Morphology and particle size
4.2.4.4 Vibrational spectra
4.2.5 Double Activated Y(Ta,Nb)O4:Eu3+,Tb3+
4.2.5.1 Sample preparation
4.2.5.2 Particle morphology and sizes
4.2.5.3 X-Ray diffraction measurement
4.2.5.4 X-ray luminescent measurement
4.2.5.5 X-ray diffraction characterization
4.2.5.6 Cathodoluminescence
4.2.5.7 VUV excitation
4.2.5.8 X-ray luminescence characterization
4.2.5.9 Luminescence mechanism in double
activated Y(Ta,Nb)O4:Eu3+Tb3+
4.2.6 Stark Levels and Selection Rules
4.2.6.1 Stark levels and selection rules for the
transitions in Tb3+ and Eu3+ (4f8 shell)
4.2.6.2 Experimental measurements
4.2.6.3 VUV excitation
4.2.6.4 X-ray excitation
4.2.6.5 Low-temperature PL measurements
4.2.7 First-Principles Electronic Structure Calculations
4.2.7.1 Samples preparation
4.2.7.2 Densities of states calculations
4.2.7.3 Experimental results
4.2.7.4 DOS and luminescence
4.2.8 Red Emission Properties of (Y,M)NbO4:Eu3+
(M:Al,Ga)
4.2.8.1 nUV excitation
4.2.8.2 X-ray excitation
4.2.9 Configurationally Coordinate Diagram and Energy Transfer Model
Transfer Model
4.2.10 Terahertz Spectroscopy in Study Y(Ta,Nb)O4-
Based Phosphors
4.2.11 Concluding Remarks
4.3 Phosphors Based on Europium Doped Oxides and Oxysulfides
4.3.1 Introductory Remarks
4.3.2 Eu3+ Activated Y2O3
4.3.2.1 Synthesis of europium doped yttrium
oxide phosphors
4.3.2.2 Structural and luminescent
characterization
4.3.3 Eu3+ Doped Y2O2–La2O2–Gd2O2
4.3.3.1 Synthesis of europium doped yttrium–
gadolinium–lanthanum oxide phosphors
4.3.3.2 Structural and luminescent
characterization
4.3.4 Eu3+ Doped Y2O2S–La2O2S–Gd2O2S
4.3.4.1 Synthesis of europium doped yttrium–gadolinium–lanthanum Oxysulfide Phosphorus
4.3.4.2 Structural and luminescent
characterization
4.3.5 Phosphors Based on YVO4:Eu3+ and (Y,Gd)VO4:Eu3+
4.3.5.1 Synthesis of (YX, Gd1-X)VO4:Eu3+ phosphor
by co-precipitation and solid state
reaction route
4.3.5.2 Structural and luminescent
characterization
4.3.6 Concluding Remarks
4.4 Yttrium and Terbium Aluminate Phosphors
Co-activated by Eu3+
4.4.1 Introductory Remarks
4.4.2 Physico-chemical Aspects Related with
the Synthesis of YAG-Based Phosphors
4.4.3 Luminescence Properties of Tb3Al5O12:Ce3+ Eu3+
4.4.3.1 Preparation of the phosphors
4.4.3.2 Measurements
4.4.3.3 Luminescence properties
4.4.4 Luminescence Mechanism and Energy-Level
Diagram
4.4.5 Quantum Efficiency of YAG and TAG Phosphors
4.5 Thiogallate Luminescent Materials
4.5.1 Introductory Remarks
4.5.2 Structural and Luminescent Properties of Calcium,
Strontium, and Barium Thiogallates
4.5.3 New Efficient Multiphase Green Phosphor
[SrGa2S4 □□ MgGa2O4]:Eu2+
4.5.4 Electron-Vibrational Interaction in 4f–5d
Optical Transitions
4.5.5 Concluding Remarks
4.6 Multiexcited Phosphors for LED Application
4.6.1 Introductory Remarks
4.6.2 Requirements of Multiexcitation
4.6.3 Double Excitation in UV LED
4.6.4 Triple Excitation in UV LED
4.6.5 Double Excitation in Blue LED
4.6.6 LED with Scattering Layer and Reflecting Medium
4.6.6.1 UV LED
4.6.6.2 Blue LED
4.6.7 Concluding Remarks
4.7 Other Luminescent Materials
4.7.1 Luminescent Properties of Ca-a-SiAION:Eu2+
4.7.2 (Ca1-xSrx)(S1-ySey):Eu2+ Phosphors with Controlled
Properties
4.7.3 Concluding Remarks
References
Appendix I: The Luminescence Literature
a. Phosphor Books
b. Phosphor Reviews
Appendix II: List of Main Abbreviations
Index