Contents
Cover
Title page
Copyright page
Preface
Part 1: Magnetic Materials
Chapter 1: Superconducting Order in Magnetic Heterostructures
1.1 Introduction
1.2 Fundamental Physics
1.3 Theoretical Framework
1.4 Experimental Status
1.5 Novel Predictions
1.6 Outlook
Acknowledgements
References
Chapter 2: Magnetic Antiresonance in Nanocomposite Materials
2.1 Introduction: Phenomenon of Magnetic Antiresonance
2.2 Magnetic Antiresonance Review
2.3 Phase Composition and Structure of Nanocomposites Based on Artificial Opals
2.4 Experimental Methods of the Antiresonance Investigation
2.5 Nanocomposites where the Antiresonance is Observed in
2.6 Conditions of Magnetic Antiresonance Observation in Non-conducting Nanocomposite Plate
2.7 Magnetic Field Dependence of Transmission and Reflection Coefficients
2.8 Frequency Dependence of Resonance Amplitude
2.9 Magnetic Resonance and Antiresonance upon Parallel and Perpendicular Orientation of Microwave and Permanent Magnetic Fields
2.10 Conclusion
Acknowledgement
References
Chapter 3: Magnetic Bioactive Glass Ceramics for Bone Healing and Hyperthermic Treatment of Solid Tumors
3.1 Bone and Cancer: A Hazardous Attraction
3.2 Hyperthermia Therapy for Cancer Treatment
3.3 Evidences of Hyperthermia Efficacy
3.4 Magnetic Composites for Hyperthermia Treatment
3.5 Magnetic Glass Ceramics
3.6 Conclusions
References
Chapter 4: Magnetic Iron Oxide Nanoparticles: Advances on Controlled Synthesis, Multifunctionalization, and Biomedical Applications
4.1 Introduction
4.2 Controlled Synthesis of Fe
3
O
4
Nanoparticles
4.3 Surface Modification of Fe
3
O
4
Nanoparticles for Biomedical Applications
4.4 Magnetism and Magnetically Induced Heating of Fe
3
O
4
Nanoparticles
4.5 Applications of Fe
3
O
4
Nanoparticles to Magnetic Hyperthermia
4.6 Applications of Fe
3
O
4
Nanoparticles to Hyperthermia-based Controlled Drug Delivery
4.7 Conclusions
Acknowledgment
References
Chapter 5: Magnetic Nanomaterial-based Anticancer Therapy
5.1 Introduction
5.2 Magnetic Nanomaterials
5.3 Biomedical Applications of Magnetic Nanomaterials
5.4 Magnetic Nanomaterials for Cancer Therapies
5.5 Relevance of Nanotechnology to Cancer Therapy
5.6 Cancer Therapy with Magnetic Nanoparticle Drug Delivery
5.7 Drug Delivery in the Cancer Therapy
5.8 Magnetic Hyperthermia
5.9 Role of Theranostic Nanomedicine in Cancer Treatment
5.10 Magnetic Nanomaterials for Chemotherapy
5.11 Magnetic Nanomaterials as Carrier for Cancer Gene Therapeutics
5.12 Conclusions
5.13 Future Prospects
References
Chapter 6: Theoretical Study of Strained Carbon-based Nanobelts: Structural, Energetic, Electronic, and Magnetic Properties of [
n
]Cyclacenes
6.1 Introduction
6.2 Computational Strategy and Associated Details
6.3 Results and Discussion
6.4 Conclusions
Acknowledgments
References
Chapter 7: Room Temperature Molecular Magnets: Modeling and Applications
7.1 Introduction
7.2 Experimental Background
7.3 Ideal Structure and Sources of Structural Disorder
7.4 Exchange Coupling Constants and Ferrimagnetic Ordering
7.5 Magnetic Anisotropy
7.6 Applications of V[TCNE]
x
7.7 Conclusions
Acknowledgments
References
Part 2: Optical Materials
Chapter 8: Advances and Future of White LED Phosphors for Solid-State Lighting
8.1 Light Generation Mechanisms and History of LEDs Chips
8.2 Fabrication of WLEDs
8.3 Evaluation Criteria of WLEDs
8.4 Phosphors for WLEDs
8.5 Conclusions
References
Chapter 9: Design of Luminescent Materials with “Turn-On/Off” Response for Anions and Cations
9.1 Introduction
9.2 Luminescent Materials for Sensing of Cations
9.3 Luminescent Materials for Sensing of Anions
9.4 Conclusion
Acknowledgments
References
Chapter 10: Recent Advancements in Luminescent Materials and Their Potential Applications
10.1 Phosphor
10.2 An Overview on the Past Research on Phosphor
10.3 Luminescence
10.4 Mechanism of Emission of Light in Phosphor Particles
10.5 How Luminescence Occur in Luminescent Materials?
10.6 Luminescence Is Broadly Classified within the Following Categories
10.7 Inorganic Phosphors
10.8 Organic Phosphors
10.9 Optical Properties of Inorganic Phosphors
10.10 Role of Activator and Coactivator
10.11 Role of Rare Earth as Activator and Coactivator in Phosphors
10.12 There are Different Classes of Phosphors, which May be Classified According to the Host Lattice
10.13 Applications of Phosphors
10.14 Future Prospects of Phosphors
10.15 Conclusions
References
Chapter 11: Strongly Confined PbS Quantum Dots: Emission Limiting, Photonic Doping, and Magneto-optical Effects
11.1 Introduction
11.2 QDs Used and Sample Preparation
11.3 Basic Properties of PbS Quantum Dots
11.4 Measuring Techniques and Equipment Employed
11.5 Photoluminescence Limiting of Colloidal PbS Quantum Dots
11.6 Photonic Doping of Soft Matter
11.7 Magneto-optical Properties
11.8 Conclusions
Acknowledgment
References
Chapter 12: Microstructure Characterization of Some Quantum Dots Synthesized by Mechanical Alloying
12.1 Introduction
12.2 Brief History of QDs
12.3 Theory of QDs
12.4 Different Processes of Synthesis of QDs
12.5 Structure of QDs
12.6 Applications of QDs
12.7 Mechanical Alloying
12.8 The Rietveld Refinement Method
12.9 Some Previous Work on Metal Chalcogenide QDs Prepared by Mechanical Alloying from Other Groups
12.10 Results and Discussion
12.11 Conclusions
References
Chapter 13: Advances in Functional Luminescent Materials and Phosphors
13.1 Introduction
13.2 Some Theoretical Aspects of the Processes of Light Absorption/Emission by Matter
13.3 Sensitization/Energy Transfer Phenomenon in Luminescence Process
13.4 Functional Phosphors
13.5 Classifications of Functional Phosphors
13.6 Solid-state Luminescent Materials for Laser
Acknowledgments
References
Chapter 14: Development in Organic Light-emitting Materials and Their Potential Applications
14.1 Luminescence in Organic Molecules
14.2 Types of Luminescence
14.3 Mechanism of Luminescence
14.4 Organic Compounds as Luminescent Material
14.5 Possible Transitions in Organic Molecules
14.6 OLED’s Structure and Composition
14.7 Basic Principle of OLEDs
14.8 Working of OLEDs
14.9 Light Emission in OLEDs
14.10 Types of OLED Displays
14.11 Techniques of Fabrication of OLEDs Devices
14.12 Advantages of OLEDs
14.13 Potential Applications of OLEDs
14.14 Future Prospects of OLEDs
14.15 Conclusions
References
Index
End User License Agreement
Guide
Cover
Copyright
Contents
Begin Reading
List of Illustrations
Chapter 1
Figure 1.1
The possible symmetry combinations of a superconducting order parameter Δ. The total Cooper pair wave function must in general be antisymmetric at equal times in order to satisfy the Pauli principle, while the particular combination of underlying symmetries governs the properties and class of superconductor. The axis for the curves displaying the two types of time-symmetries (even and odd frequency) is
frequency,
essentially obtained by Fourier-transforming the relative time-coordinate
t
=
t
1
–
t
2
for electrons 1 and 2 in the Cooper pair.
Figure 1.2
Left panel
: Typical density of states
D
(
ε
) vs. quasiparticle energy
ε
measured on the non-superconducting side of an SF bilayer setup when the singlet proximity effect dominates.
Middle panel
: Typical density of states measured on the non-superconducting side of an SF bilayer setup when the triplet proximity effect dominates.
Right panel
: Spin-split density of states in a thin-film superconductor exposed to an in-plane magnetic field. Here shown for a externally induced Zeeman field of
h
= 0.3Δ
0
. In all cases the background density of states of a normal metal is here normalized as
D
(
ε
) = 1.
Figure 1.3
Left panel:
The critical supercurrent can display two types of behavior in ferromagnetic Josephson junctions. If no long-ranged triplet pairs are generated (due to
e.g
. magnetic inhomogeneities), the supercurrent is suppressed very quickly with increasing junction length
L
F
(note the logarithmic scale). In contrast, if triplet pairs with spin-polarization aligned with the magnetization direction are created, these can carry a long-ranged current through the system which is only weakly suppressed with increasing
L
F
. Right panel:
Magnetic control over the superconducting critical temperature
T
c
and its characteristic behaviour in two types of spin-valve junctions: FSF and SFF.
Figure 1.4
Left panel:
In a ϕ
0
-junction, the entire current-phase relation is shifted so that a net supercurrent flows even at zero phase difference.
Middle panel:
Magnetic control of superconducting
T
c
in the presence of Rashba and Dresselhaus spin-orbit coupling requires only one single homogeneous ferromagnet, in contrast to all previous proposals which have required two or more magnetic materials. Here,
T
c,0
is the bulk superconducting critical temperature and the angle
θ
is given in degrees.
Right panel:
Giant triplet proximity effect in spin-orbit coupled Josephson junction at
π
phase difference. Note the absence of a proximity effect without spin-orbit coupling at
π
phase difference for conventional SNS or SFS junctions.
Chapter 2
Figure 2.1
Electron microscopic image of structure of nanocomposite based on the artificial opal with the particles of nickel–zinc ferrite spinel (a) and particles of cobalt and palladium (b).
Figure 2.2
XRD pattern of nanocomposite sample No. 155/7-700 with the particles of cobalt and palladium.
Figure 2.3
The scheme of magnetic antiresonance observation in the transmission and reflection of waves from the sample in the waveguide (a) and upon the placement in the resonator (b).
Figure 2.4
The magnetic antiresonance upon the reflection of waves for nanocomposite No. 169/6-700 with the metal particles (a); the dependence of coefficient of wave’s transmission through the resonator with the nanocomposite containing dielectric particles of nickel–zinc ferrite Ni
0.5
Zn
0.5
Fe
2
O
4
(b).
Figure 2.5
The field dependence of changes of modules of transmission (a) and reflection coefficients (b) for the nanocomposite with the metallic particles of cobalt and palladium.
Figure 2.6
The magnetic field dependence of changes of modules of transmission (a) and reflection coefficients (b) for the nanocomposite with the dielectric particles of neodymium ferrite garnet.
Figure 2.7
The field dependence of changes of modules of transmission (a) and reflection coefficients (b) for the nanocomposite with the particles of lanthanum–strontium (La–Sr) manganite.
Figure 2.8
The frequency dependences of real (a) and imaginary (b) parts of effective permeability, calculated by formulas (2.10) and (2.11) for the nanocomposite with the particles of nickel–zinc ferrite spinel Ni
0
.
5
Zn
0
.
5
Fe
2
O
4
.
Figure 2.9
The frequency dependences of transmission (a) and reflection coefficients (b), which are calculated by formulas (2.13) and (2.14) for the nanocomposite with the particles of nickel–zinc ferrite spinel Ni
0.5
Zn
0.5
Fe
2
O
4
.
Figure 2.10
The dependences of transmission, reflection coefficients and dissipation, calculated by formulas (2.13) and (2.14) for the nanocomposite with the particles of nickel–zinc ferrite spinel Ni
0
.
5
Zn
0
.
5
Fe
2
O
4
for three frequencies
f
= 26 GHz (a),
f
= 32 GHz (b), and
f
= 38 GHz (c).
Figure 2.11
The giant antiresonance in the nanocomposite with Ni–Zn ferrite particles. The dependences of reflection coefficient from the plate of 1.9 mm in thickness, measured at several frequencies of millimeter waveband.
Figure 2.12
A schematic representation of frequency dependences of reflection coefficient upon
H
= 0 and
H ≠
0. The minimums positions are designated as
f
1
and
f
3
.
Upon
f
<
f
2
when increasing the magnetic field the reflection coefficient increases. Upon
f
<
f
1
when increasing the frequency
f
the value of changes of reflection coefficient should increase, and upon
f
1
<
f
<
f
2
– should decrease.
Figure 2.13
The field dependence of transmission coefficients through the plate of Ni–Zn ferrite: parallel orientation of
H||H
~
(a) and perpendicular orientation
H
⊥
H
~
(b).
Figure 2.14
The field dependence of reflection coefficients from the plate of Ni–Zn ferrite: parallel orientation of
H||H
~
(a) and perpendicular orientation
H
⊥
H
~
(b).
Chapter 3
Figure 3.1
Tumors induce the release of various factors regulating bone formation at different steps of osteoblast development. Bone morphogenetic proteins (BMPs), Wingless-type MMTV integration site family member (WNTs), and TGF-
β
provide signals to mesenchymal stem cells to differentiate towards osteoblast lineage. Osteoblast progenitors and pre-osteoblastic cells are sensitive to positive osteoblastic factors produced by tumor cells: BMPs, endothelin 1 (ET1), insulin-like growth factors (IGFs), platelet-derived growth factor (PDGF), urinary plasminogen activator (uPA), and fibroblast growth factors (FGFs), as well as the negative regulator dickkopf 1 (DKK1). Osteoblast-associated transcription factors include RUNX2, osterix (OSX), and activating transcription factor 4 (ATF4).
Figure 3.2
Different mechanisms of immune activation induced by locally heating tumors. (a) Heated tumor cells are induced to release HSPs, which activate NK cells and APCs which take up the HSP–antigen complex and cross-present the antigen to CD8+ T cells. (b) Heated tumor cells increase the surface expression of MICA, a NKG2D ligand, and MHC class I, making the tumor cells more sensitive to lysis by NK cells and CD8+ T cells, respectively. (c) The tumor vasculature becomes more permeable and may have increased adhesion molecule expression after heating, which may facilitate better trafficking of immune cells between the tumor and dLN. (d) Finally, heated tumor cells release exosomes containing potential tumor antigens that APCs recognizes and presents to the CD8+ T cells.
Figure 3.3
SEM images of composite bone cements. The SC 45 powders appear uniformly distributed into the polymeric matrix, without signs of agglomeration. (a) The compositional analyses evidence the presence of the peaks characteristic of the glass ceramic and of the ZrO
2
, together with the PMMA peaks. In (b) is also possible to appreciate the presence of the ferromagnetic counterpart. Bar scale = 100 μm (magnification 200×) for (a) and 5 μm (magnification 10,000×) for (b).
Figure 3.4
Field emission scanning electron microscopy (FESEM) micrograph of human osteoblasts-like Mg63 cells (white circles) cultured on ferrimagnetic and bioactive composite cement (left panel) and EDS analysis of calcium phosphate crystal grown onto specimen surface (right panel). Cells successfully adhered to the cements surface where the HAp typical Ca and P peaks were detected. Bar scale = 10 μm (magnification 5000×).
Figure 3.5
Bone heating ability of glass ceramics (adapted from ref. [120]).
Figure 3.6
SEM image of magnetite crystals after glass ceramic etching. Bar scale = 100 μm (magnification 2000×).
Figure 3.7
Room temperature hysteresis cycle up to 10 kOe for a coprecipitation-derived magnetic glass ceramic (sample A) and magnetite (adapted from ref. [132]).
Chapter 4
Figure 4.1
(a–c) TEM images and (d–f) corresponding SEM images of cross-section of Fe
3
O
4
nanoparticles prepared by solvothermal process for 6, 8, and 12 h of processing times, respectively, showing the evolution of porous/hollow structures, and (g) schematic of the hollow structure development in solvothermal process. The chemical conversion caused the nonuniformities of tiny grains and the empty spaces within the spheres and thus enhanced the outward migration and relocation of the core grains toward the outer layer, resulting in generation and development of hollow structure.
Figure 4.2
Illustration depicting the modification of various materials onto the surface of magnetic nanoparticle cores.
Figure 4.3
Illustration of multifunctional magnetic nanoparticles.
Figure 4.4
(a) Schematic illustration of domain structure and magnetism of magnetic nanoparticles as a function of size. (b and c) Schematic illustrations of the theoretical magnetization versus applied magnetic field curves for superparamagnetic and ferromagnetic nanoparticles, respectively.
Figure 4.5
Magnetism and general mechanisms for heat generation of magnetic nanoparticles.
Chapter 5
Figure 5.1
Size scale of magnetic nanomaterials (MNMs) as compared to biomolecules. MNM can be adapted to include biomolecules, drugs, or targeting and imaging molecules to form targeted MNM theranostic agents.
Figure 5.2
Different types of drugs loaded/conjugated MNMs.
Figure 5.3
Animal trial data on hyperthermia treatments, showing preferential heating of a tumor using intravascularly infused ferromagnetic microspheres; (■) tumor edge, (◊) tumor centre, (Δ) normal liver 1–2 cm from tumor, (x) alternative lobe, and (◊) core body temperature.
Figure 5.4
Functional architecture of MNMs and theranostic modalities.
Chapter 6
Figure 6.1
Chemical structures of some carbon-based nanohoops used as model systems:
n
implies the number of constituting or fused benzene rings, for [
n
]CPP, [
n
]CC, or [
n
]cyclophenacenes ([
n
]CPC), while for [5,7]
n
cyclocenes ([5,7]CC) means the number of fused azulene rings.
Scheme 6.1
Main characteristics of the self-consistent methods employed along the study. Note that only the relevant frontier MO and their occupation are shown.
Scheme 6.2
Characteristic parameters for [
n
]CC systems, being r
CC
parallel
and r
CC
zig-zag
the bond length parallel to the axial axis and the peripherally distributed “zig-zag” bond length, respectively, and ω the angle which shows the relative inclination of the inner benzene units.
Scheme 6.3
Model reaction employed to calculate the strain energy of [
n
]CC systems.
Figure 6.2
Evolution of the calculated strain energy with the diameter of the nanobelt in [
n
]CC and [
n
]CPP compounds.
Figure 6.3
Relative energy between spin states in [
n
]CC compounds, as calculated at the M06-2X/6-31+G* level (see text for details). The dashed lines are a guide to the eye.
Figure 6.4
Isocontour plots of the (left) HOMO and (right) single-occupied molecular orbitals (SOMO) for the [6]CC molecule, as obtained by a RKS and BS-KS solutions, respectively. The size and color describe the amplitude and sign, respectively, of the lobes of the orbitals.
Scheme 6.4
Relative (and simplified) position of the hypersurfaces of the low-lying energy states when an open-shell triplet state is energetically favored.
Figure 6.5
Vertical absorption energies in [
n
]CC compounds to the lowest singlet and triplet state, as calculated at the TDA-M06-2X/6-31+G* level (see text for details). The dashed lines are a guide to the eye.
Chapter 7
Figure 7.1
Magnetization as a function of temperature for V[TCNE]
x
·
y
(solvent) [solvent = CH
2
Cl
2
(○), hexane (x), and PhMe (+), and PhCF3 (•)] in an applied field of 5 Oe. From Ref. [33].
Figure 7.2
Schematic structure of cyanocarbon acceptors used as building blocks in high-temperature molecular magnets. From left to right: tetracyanoethelene (TCNE), tetracyanobenzene (TCNB), tetracyanopyrazene (TCNP), and 7,7,8,8-tetracyanoquinodimethane (TCNQ).
Figure 7.3
Schematic structure of mono- and di-substituted cyanocarbon acceptors used as building blocks in high-temperature molecular magnets. From left to right and then top to bottom: 2-fluoro-, 3-fluoro-, 4-fluoro-, 2,4-difluoro-, 2,6-difluoro-, and 3,5-difluorophenyltricyanoethylene. From Ref. [37].
Figure 7.4
Ordering temperature,
T
c
, and coercivity,
H
cr
, as a function of
x
for V
x
Ni
1–x
[TCNE]
2·
γ
(CH
2
Cl
2
). From Ref. [42].
Figure 7.5
(a) Illustration of the binding of [TCNE] – and [TCNE]
2–
to up to four V
II
ions, based on Ref. [18]. (b) The environment around the V
II
ion, indicating that the six N atoms surround the metal ion at an average distance of 2.084 Å, inspired by Refs [8, 22].
Figure 7.6
Electron density drawn at 0.025 e/bohr
3
of some key molecular orbitals of the V
II
[TCNE]
4
system, calculated by DFT and represented in the order of increasing energy. From Ref. [48].
Figure 7.7
Schematic representation of the optimized V[TCNE]
2
3D structure displaying (a) a plane of tetra-coordinated and (b) bis-coordinated TCNE radical anions. The vanadium, carbon, and nitrogen atoms are represented as yellow, gray, and blue balls, balls, respectively. From Ref. [49].
Figure 7.8
Schematic representation of the ideal structure of V[TCNE]
2
: (a) molecular V[TCNE]
2
unit, (b) 2D structure illustrating the 1:2 metal to ligand stoichiometry, and (c) 3D stacking along the
c
direction of the plains. The vanadium, carbon, and nitrogen atoms are represented in yellow, gray, and blue balls, respectively. From Ref. [57].
Figure 7.9
Optimized structure of the ideal V[TCNE]
2
lattice, viewed in perspective, along the
c
axis. The vanadium, carbon, and nitrogen atoms are represented in yellow, gray, and blue balls, respectively.
Figure 7.10
Selected molecular fragments cut from the proposed V[TCNE]
2
structure illustrating: (A) the six coordination of the V(II) ion, (B) a tetra-connected moiety located in the
a–c
crystallographic plane, and (C) a bis-connected ligand along the
b
axis with the TCNE plane rotated by about 20° with respect to the
b–c
crystallographic plane. The vanadium, carbon, and nitrogen atoms are represented in yellow, gray, and blue balls, respectively.
Figure 7.11
Schematic drawings of the V[TCNE]
x
structure illustrating the disorder caused by the chirality. The blue building blocks represent the tetra-connected TCNEs, whereas the yellow ones the bis-connected TCNEs. The 3D structure is the result of the combined vertical stacking and horizontal sliding of 2D layers. (a) The two mirror images represent enantiomeric networks, which differing only by the sliding direction performed to allow for tetra-coordination of the TCNEs. (b) The static disorder results from the racemic mixture of the two enantiomeric structures. A background reference layer is represented in grey. From Ref. [57].
Figure 7.12
Perspective view of the structures of V[TCNE]
2
lattice along the
c
axis: (a) the DFT-optimized structure, (b) structure altered with a 180° rotation, and (c) a 90° rotation of the bis-connected
μ
2
-TCNE units from the upper sheet around the
b
axis; the
μ
2
-TCNE bridges from the lower sheet are kept fixed. The vanadium, carbon, and nitrogen atoms are represented in yellow, gray, and blue balls, respectively. From Ref. [57].
Figure 7.13
Energy of the low-spin (ferrimagnetic) ground state as a function of the rotation angle,
ψ
, of the bi-connected TCNE, obtained by DFT band calculations of V[TCNE]
2
structures. Note the following equivalences: 1 hartree ↔ 27.2107 eV ↔ 315777 K and 1 cm
−1
↔ 0.695 K. From Ref. [57].
Figure 7.14
Schematic representation of typical excitations in the case of the [TCNE]-V-[TCNE] model systems, illustrating the various contributions to superexchange: (a) potential exchange, (b) kinetic exchange, (c) spin polarization, and (d and e) correlation exchange. From Ref. [56].
Figure 7.15
Electron density drawn at 0.015 e/bohr
3
of some key molecular orbitals of the {(HCN)
5
V(II)[TCNE]
−
}
+
dinuclear, calculated by DFT and represented in the order of increasing energy. The structure of the {(HCN)
5
V(II)[TCNE]
−
}+ dinuclear is represented in the inset. The vanadium, carbon, nitrogen, and hydrogen atoms are represented by a large black sphere, and yellow, gray, and blue balls, spheres, respectively.
Figure 7.16
Schematic representation of the interactions in a V[TCNE]
2
trinuclear of 3/1, 1/2, and 1/2 spin carriers. The exchange parameters
J
12
and
J
23
describe the V
II
–[TCNE] interactions in various spatial configurations, whereas
J
13
stands for the next-nearest-neighbor interaction between the TCNEs. We represented here a general triangular conformation, but the same scheme holds for linear cases.
Figure 7.17
The electronic structure of V[TCNE]
2
in its ground-state anti-FM configuration. The energy scale (eV) has been normalized and expressed relatively to the Fermi energy,
E
F
.
On the
x
axis the points labeled as Γ, B, G, and F correspond to the
k
points of the first Brillouin zone of the triclinic and monoclinic Bravais lattices whose absolute coordinates are (0,0,0), (1/2,0,0), (0,0,1/2), and (0,1/2,0), respectively. From Ref. [49]. From Ref. [49].
Figure 7.18
DOS curves for
α
and b bands (solid and dotted line respectively), as resulted from unrestricted DFT/BLYP/6-31G* calculations on the optimized V[TCNE]
2
crystal structure, in its ground-state anti-FM configuration (left). Electronic structure calculated by unrestricted DFT for the TCNE(
a
)–V–TCNE(
b
) trinuclear cut from the optimized geometry (orbital shapes in the center and corresponding energies in the right). Electron densities of MOs determined for the trinuclear (0.03 e/bohr
3
).
Figure 7.19
Spin population (left), orbital shapes drawn at 0.015 e/bohr
3
(center) and energies (right) of selected optimized MCSCF orbitals from the CASSCF(9,9) calculations of the [TCNE](
a
)–V–[TCNE](
a
) trinuclear. From Ref. [56].
Figure 7.20
Orbital shapes drawn at 0.01 e/bohr
3
of the highest five singly occupied optimized MCSCF orbitals resulting from the CASSCF(9,9) calculations of the various symmetric trinuclears: [TCNE](
a
)–V–[TCNE](
a
) (left), [TCNE](
b
)–V–[TCNE](
b
) (center), and [TCNE](
c
)–V–[TCNE](
c
) (right). From top to bottom, displayed are the HOMO to HOMO-4, for each symmetric trinuclear system. From Ref. [56].
Figure 7.21
Orbital shapes drawn at 0.01 e/bohr
3
of the highest five singly occupied optimized MCSCF orbitals resulting from the CASSCF(9,9) calculations of the various asymmetric trinuclears: [TCNE](
a
)–V–[TCNE](c) (left), [TCNE](
a
)–V–[TCNE](
b
) (center), and [TCNE](
b
)–V–[TCNE](
c
) (right). From top to bottom, displayed are the HOMO to HOMO-4, for each asymmetric trinuclear system. From Ref. [56].
Figure 7.22
Spin population (left), orbital shapes drawn at 0.015 e/bohr
3
(center) and energies (right side) of selected canonical orbitals from the CASSCF(11, 9) calculations of the TCNE(
a
)–Mn–TCNE(
a
) trinuclear.
Figure 7.23
Orbital shapes drawn at 0.015 e/bohr
3
of selected canonical orbitals from the CASSCF(9,11) calculations of the V–TCNE–V trinuclear, represented in the order of increasing energy.
Figure 7.24
Geometric frustration in Ising antiferromagnets on a triangular lattice (a) and random frustration in a random exchange Ising system on square lattice (b). The lines between adjacent spins are continuous for anti-FM exchange and dashed for FM exchange. The question marks suggest that those spins cannot minimize simultaneously the interactions with all the nearest neighbors.
Figure 7.25
Diagram illustrating a classification of disordered magnets based on both frustration and degree of disorder. For details see Ref. [2].
Figure 7.26
Schematic representation of spin configurations in some disordered magnets: (a) dilute ferromagnet, (b) speromagnet, (c) dilute ferrimagnet, and (d) sperimagnet. For details, see Refs [2, 57, 107].
Figure 7.27
Exchange coupling constant,
J
, as a function of
ψ
, determined for V[TCNE]
2
model structures by the BS-DFT approach through band structure calculations. From Ref. [57].
Figure 7.28
(a) The
4
F
J
state is split by the octahedral LF into A
2
, T
1
and T
2
quartet states and distortions lead to further splittings. SO interactions in second order partially remove the degeneracy of the
4
A
2
leading to two Kramers’ doublets. (b) Zeeman interactions cause a linear response to the applied field. From Ref. [57].
Figure 7.29
Polar diagrams of the state-specific magnetization functions, for (a) {V[MCNE]
5
}
2+
and (b) {V[MCNE]
6
}
2+
, and the corresponding ZFS schemes, obtained via CASSCF+SO calculations. The
M
(
θ,φ
) functions are represented in Cartesian frames, in Bohr magneton units. The molecular skeleton is immersed with arbitrary scaling. From Ref. [57].
Figure 7.30
Schematic view of a DOS in the organic-based magnetic semiconductor V[TCNE]
x
. On the basis of X-ray, electron and neutron spectroscopies, it is determined that the valence band (v.b.) of V[TCNE]
x
is derived from the 3
d
(
t
2g
) levels of vanadium and the conduction band (c.b.) stems from the
π*+U
c
levels of TCNEs. The DOS in V[TCNE]
x
features highly spin-polarized valence and conduction bands with the same spin orientation and nonoverlapping spin-polarized bands. From Ref. [10].
Figure 7.31
Different spin valve designs and their possible resistances. (a) V[TCNE]
x
sandwiched between two identical FM contacts. (b) V[TCNE]
x
sandwiched between two different FM contacts. (c) V[TCNE]
x
and a FM contact sandwiching an organic semiconductor. Since V[TCNE]
x
is a semiconductor, a metallic contact on top of V[TCNE]
x
is needed. (d) The chemical structure of TCNE. From Ref. [137].
Figure 7.32
Highly resolved STM images and structural models of (a) TCNE, (b) V–TCNE, (c) V[TCNE]
2
, (d) V
2
TCNE@27°, and (e) V
2
TCNE@11° on Ag(100). The models are derived from the STM images. Note that V
2
TCNE@11° has a shorter V–V distance compared to V2TCNE@27°. From Ref. [138].
Figure 7.33
(a) Schematic view of a hybrid magnetic tunnel junction of V[TCNE]
x
/rubrene/LAO/LSMO. The two FM layers of different coercivity
H
c1
and
H
c2
are decoupled by the hybrid barrier of rubrene/LAO. (b) The magnetoresistance curves of a V[TCNE]
x
/rubrene/LAO/LSMO junction measured at 100 K with a bias field of 0.5V. The line with up (down) triangles are the data collected with increasing (decreasing) field. The magnetizations of V(TCNE)
x
(500 nm) and LSMO (80 nm) on pseudo-cubic (001) NdGaO3 substrate are measured from individual films by SQUID magnetometry. From Ref. [10].
Figure 7.34
(a) The schematic device structure. On the right side is the optical image of the cross-section. Rubrene (50 nm) is deposited in the center area of 0.2 mm by 0.2 mm surrounded by SiO
2
. Fe film (30 nm) will be deposited on top of the rubrene layer. (b) Chemical structure of rubrene (C42H28). (c) Magnetic hysteresis loops of LSMO (50 nm) on LSAT (0 0 1) substrate and Fe (30 nm) on glass substrate. (d) Temperature-dependent resistance (OFF state) of the LSMO (50 nm)/LAO/rubrene (50 nm)/Fe (30 nm) junction. From Ref. [142].
Figure 7.35
Schematic view of an organic spin valve of Al/V[TCNE]
x
/rubrene/V[TCNE]
x
/Al. Based on Ref. [11].
Figure 7.36
(a) I–V curves for both bare LED (triangles) and V[TCNE]
x
spin-LED (diamonds) devices at T = 60 K. (b) Typical EL spectrum of a V[TCNE]
x
spin-LED device (I = 0.5 mA, V +18.5 V) at T = 60 K. The shaded areas in the spectrum indicate the region of polarization integration over the QW HH and LH peaks, respectively. Inset: A schematic of the V[TCNE]
x
spin-LED device structure. From Ref. [12].
Chapter 8
Figure 8.1
Schematic structure of LEDs package. Adapted from Ref. [3], reproduced with permission.
Figure 8.2
The history of the luminous efficacy in incandescent, halogen, fluorescent, and sodium–vapor lamps and WLEDs. Adapted from Ref. [12], reproduced with permission.
Figure 8.3
Schematic diagram of the three main white-lighting strategies. (a) Tricolor LEDs combined by red, green, and blue (RGB) LED chips. (b) A three-phosphor strategy with a UV LED coated with RGB phosphors. (c) A blue LED with yellow or other phosphors.
Figure 8.4
Different methods of fabricating white light with blue LED and phosphors. Adapted from Ref. [1], reproduced with permission.
Figure 8.5
(a) 1931 CIE diagram with Planckian locus. The lines on Planckian locus are known as isothermal lines. (b) Reflectivity spectra of eight test samples used for calculation of color rendering indices. Adapted from Ref. [3], reproduced with permission.
Figure 8.6
At elevated temperatures, overlap between the ground state and excited state energy bands due to lattice relaxation allows electrons to dissipate absorbed energy without re-emission of a photon. Image courtesy Dow Electronic Materials.
Figure 8.7
Energy level diagram of Ce
3+
and Eu
2+
.
Chapter 9
Figure 9.1
Schematic representation of a luminescent sensor.
Figure 9.2
The chemical structures of the different luminophores using in luminescent materials.
Figure 9.3
Structures of luminescent sensor
1–6
for alkaline metal ions.
Figure 9.4
Structures of luminescent sensor
7–13
for alkaline earth metal ions.
Figure 9.5
Luminescent probes
14–20
for Zn
2+
and Cd
2+
ions.
Figure 9.6
Luminescent probes
21–26
for Mn
2+
and Fe
2+
ions.
Figure 9.7
Luminescent probes
27–33
for Ni
2+
and Co
2+
ions.
Figure 9.8
Luminescent probes
34–38
for Cu
2+
ion.
Figure 9.9
Luminescent probes 39–45 for Hg
2+
ion.
Figure 9.10
Luminescent probes
46–50
for Pb
2+
ion.
Figure 9.11
Luminescent probes
51–55
for Fe
3+
ion.
Figure 9.12
Luminescent probes
56–59
for Cr
3+
ion.
Figure 9.13
Luminescent probes
60–66
for Al
3+
ion.
Figure 9.14
Luminescent probes
67–72
for halides.
Figure 9.15
Luminescent probes
73–79
for cyanide, sulfide, bisulfate, nitride, and phosphate anions.
Chapter 10
Figure 10.1
Light emission mechanism in phosphor particles.
Figure 10.2
Schematic energy level scheme of the luminescent ion.
Figure 10.3
Showing luminescent ion A in its host matrix.
Figure 10.4
Luminescent material showing energy transfer from sensitizer S to an activator A.
Figure 10.5
Configuration coordinate graph showing the excited state and vibrational states. The ground state (g) has the equilibrium distance.
Figure 10.6
Nonradiative transitions.
Figure 10.7
Showing Franck–Condon or Stoke shift.
Figure 10.8
Showing different energy levels of lanthanides(III) ions.
Figure 10.9
Mechanism of various transitions in Eu
3+
and Eu
2+
ions.
Figure 10.10
Showing the role of coactivator in the process of luminescence.
Chapter 11
Figure 11.1
TEM images of samples A and B: (a) 2.5±0.3
nm,
(b) 5.0±1.0
nm
oleic acid capped PbS QDs, and (c) SEM image of 2.0±0.4
nm
PbS QDs (sample D).
Figure 11.2
X-ray patterns of PbS QDs of various sizes. The reflections of the Galena structure are observed for sizes as small as 2.1 nm. For clarity, the spectra are normalized and shifted.
Figure 11.3
BOMEM spectrometer with periphery able to measure the QD PL at various temperatures covering the range of 8–320 K.
Figure 11.4
Optical cryostat mounted on a metal stand keeping a distance of a quarter inch between the base of the cryostat and the BOMEM body.
Figure 11.5
Schematic diagram of magneto-optical TR and RE measurements.
Figure 11.6
PL spectra of sample D displayed for selected laser intensities at 5 K. The symbols represent the measurements and the lines Gaussian fits. The arrow indicates the blue shift of the spectra for increasing
I
ex
.
Figure 11.7
(a) Peak and (b) integral PL intensity deduced from the Gaussian fits in Figure 11.6 versus
I
ex
. The symbols represent the measurements, while the lines are fits done with Eq. (11.1).
Figure 11.8
Comparison of the PC trend of PbS nanowires and the
I
PL
trend in Figure 11.7. The PC data are deduced from Ref. [48]. The broken and dotted lines are fitted with Eq. (11.1). Both data sets show identical trends.
Figure 11.9
Schematic of the BMS of p-type PbS QDs. The picture shows the change of the electronic state from (a) weak, (b) medium, and (c) intense optical excitations. The increasing optical stimulus empties the states at the acceptor level (AL) closely located to the VB by transferring the electrons to the CB. This transfer increases
E
PL
and successively moves the Fermi energy (
E
F
) into the CB.
Figure 11.10
Two-photon excited photoluminescence (TPL) of sample C measured with the corresponding impinging laser intensities noted to the right. The emission spectra were recorded according the description in section 11.4.2 in reflection (RE) geometry. The solid line represents the measurements and the dotted lines Gaussian fits. The oblique arrow following the peak emission indicates the blue shift of the spectra.
Figure 11.11
TPL of sample C measured with the corresponding laser intensities noted to the right. The emission spectra were recorded in transmission (TR) geometry as described in section 11.4.2. The lines and arrow have the equivalent meaning as in Figure 11.10.
Figure 11.12
The symbols represent
E
PL
versus
I
ex
measured in RE and TR geometries deduced from the fitted Gaussian profiles in Figures 11.10 and 11.11, and the lines are fits carried out with Eq. (11.3).
Figure 11.13
FWHM versus
I
ex
measured in RE and TR geometry. The symbols represent the experimental data extracted from the fitted Gaussian profile in Figures 11.10 and 11.11, while the lines are linear fits.
Figure 11.14
Peak and integral PL intensities deduced from the Gaussian fits in Figures 11.10 and 11.11 versus
I
ex
. The symbols represent the measurements, while the solid and broken-dotted lines are fitted with Eq. (11.1). Error bars closely coincide with the symbol size.
Figure 11.15
The RE spectra of sample A, which divulge a clearly visible red shift of 23 meV with increasing B up to 0.784 T. The tilted arrow indicates the red shift of the spectra. The solid and broken-dotted lines represent the experimental results and Gaussian fits using Eq. (11.4), respectively.
Figure 11.16
RE spectra of industrial polished lead for various values of
B.
Figure 11.17
Plot of the
B
dependence of RE at
E
min
. and
E
min
. itself in Figure 11.16.
Figure 11.18
The RE spectra of sample
B
showing a redshift of ~7 meV (visualized by the arrow) with increasing
B
from 0.024 to 0.784 T. Symbols and broken-dotted lines represent the measurements and fits with Eq. (11.4), respectively. The dips in the spectra at 0.91 eV are caused by the Ge detector.
Figure 11.19
The TR spectra of sample A. Visualized by the arrow, the spectra show a red shift of 9 meV with increasing
B
from 0.04 to 1 T. The broken lines represent the Gaussian fits using Eq. (11.4).
Figure 11.20
Shift of E
g
versus
B
of sample A in RE and TR geometries. The fit of the trends performed with Eqs (11.15) and (11.19) are visualized by the broken and solid lines.
Figure 11.21
The RE and TR spectra of sample C show hardly alterations with increasing
B
up to 0.5 T.
Figure 11.22
PL intensity of sample C versus energy for different B values. Increasing
B
clearly reduces the emission intensity.
Figure 11.23
FWHM versus
B
of the PL spectra in Figure 11.22. The symbols are extracted from the Gaussian fits in Figure 11.22, and the lines are linear fits. The error bars coincide with the symbol size.
Figure 11.24
Emission intensity decrease observed in RE and TR geometries. The symbols are extracted from the Gaussian fits in Figure 11.22, and the lines are linear fits. The dotted arrow indicates the increase in
B
.
Chapter 12
Figure 12.1
Schematic diagram representing DOS (N(E)) with respective energy (E) for (a) 3D (three-dimensional) bulk semiconductor, (b) 2D (2-dimensional), (c) 1D (one-dimensional), and (d) 0D (zero-dimensional) nanostructures [26].
Figure 12.2
Schematic representation of synthesis of nanoparticles by top-down and bottom-up approaches [29].
Figure 12.3
Cubic zinc–blende (ICSD 77090) (left) and hexagonal wurtzite (ICSD 67453) (right) structures ZnS.
Figure 12.4
High-energy planetary ball mill (Fritsch Planetary pulversiette-5 classic line with 4 grinding bowl fasteners) [40].
Figure 12.5
XRD patterns of unmilled (0 h) and ball-milled Zn and S powders (Zn:S=1:1) for different durations. ZnS(C) and Zn(H) denote zinc blende and wurtzite structures respectively. [Reproduced with permission from [64] Copyright (2009) AIP Publication LLC.]
Figure 12.6
(a) Coexistence of a minor hexagonal phase with a major cubic phase of ZnS, milled for 3.5 h as revealed from Rietveld analysis. I
C
and I
O
represent computed and observed (experimental) patterns respectively. (b) The presence of both cubic and hexagonal phases in 3.5 h milled ZnS and formation of single cubic phase ZnS in 20 h milled sample. [Reproduced with permission from [64] Copyright (2009) AIP Publication LLC.]
Figure 12.7
Phase transformation kinetics of cubic (C) and hexagonal (H) ZnS with increasing milling time after the formation of ZnS phase. [Reproduced with permission from [64] Copyright (2009) AIP Publication LLC.]
Figure 12.8
(a) Shifting in peak positions of ZnS(C) in either side with respect to its bulk counterpart. Solid and dotted vertical lines represent the peak positions of bulk and milled ZnS(C) respectively. (b) HRTEM image of cubic (111) of ZnS showing different planar defects- (i) zone I: extrinsic stacking fault, (ii) zone II: intrinsic stacking fault and (iii) zone III: twin fault. [Reproduced with permission from [64] Copyright (2009) AIP Publication LLC.]
Figure 12.9
(a) Bright field TEM showing core (cubic)–shell (hexagonal) ZnS in 10 h milled sample, (b) HRTEM image showing the presence of (111) plane of cubic ZnS in the lattice. [Reproduced with permission from [64] Copyright (2009) AIP Publication LLC.]
Figure 12.10
Rietveld whole profile fitted output XRD patterns of unmilled and ball-milled equimolar powder mixture of Zn and Te. Dotted and solid lines represent observed (I
O
) and computed (I
C
) spectra respectively. Residue (I
O
–I
C
) of each profile fitting is plotted corresponding to each pattern. Peak positions corresponding to each phase is marked at the bottom. [Reproduced with permission from Elsevier.]
Figure 12.11
(a) Variation and (b) distribution of particle size of ZnTe with respect to milling time. [Reproduced with permission from Elsevier.]
Figure 12.12
(a) Variation and (b) distribution of r.m.s lattice strain for different hour milled ZnTe. L = na
3
, n = harmonic number, a
3
= lattice parameter. [Reproduced with permission from Elsevier.]
Figure 12.13
(a) Variation of stacking fault probabilities of cubic ZnTe with changing milling time. (b) HRTEM images of 15h milled ZnTe QDs depicting the existence of different kinds of stacking and twin faults generated in the stacking sequence of (111) planes of cubic phase: (i) zone (a): intrinsic (
α′
), (ii) zone (b): extrinsic stacking fault (
a″
), and (iii) zone (c): twin fault (
β
) is created. [Reproduced with permission from Elsevier.]
Figure 12.14
(a) Output profile of Rietveld refinement of XRD data of unmilled and ball-milled stoichiometric powder mixture of Cd and Te for different durations. (b) Complete formation of stoichiometric CdTe nanocrystals after 15 min of milling. Dotted and continuous lines represent observed (I
O
) and computed (I
C
) patterns, respectively. (I
O
–I
C
) represents residue of the refinement. [Reproduced with permission from [66] Copyright (2009) AIP Publication LLC.]
Figure 12.15
(a) Shifting in peak positions of different lattice planes on either side of 4h milled cubic CdTe nanocrystals with respect to its bulk counterpart. (b) Variation of intrinsic (
α′
), extrinsic (
α″
), and twin (
β
) faults with increasing milling time in ball-milled CdTe. (c–d) HRTEM image showing the presence of planar defects in 4 h ball-milled cubic CdTe lattice. [Reproduced with permission from [66] Copyright (2009) AIP Publication LLC.]
Figure 12.16
Variations of particle size and r.m.s. lattice strain in ball-milled CdTe nanocrystals with time of milling. [Reproduced with permission from [66] Copyright (2009) AIP Publication LLC.]
Figure 12.17
XRD patterns of Cd
x
Zn
1−x
S (for different x) just at their time of formation. CdZnS(C) and CdZnS(H) represent cubic and hexagonal phases, respectively. [Reproduced with permission from [68] © IOP Publishing. All rights reserved.]
Figure 12.18
Rietveld simulated XRD patterns of (a) 0.5h and (b) 15h milled Cd
0.5
Zn
0.5
S considering only hexagonal and cubic phases respectively. [Reproduced with permission from [68] © IOP Publishing. All rights reserved.]
Figure 12.19
Variation of lattice parameters of cubic and hexagonal ternary Cd
x
Zn
1−x
S as a function of increasing Zn concentration. [Reproduced with permission from [68] © IOP Publishing. All rights reserved.]
Figure 12.20
Variation in time of formation of ternary Cd
x
Zn
1−x
S with different concentrations of Zn. [Reproduced with permission from [68] © IOP Publishing. All rights reserved.]
Figure 12.21
Variation of mol fraction of cubic and hexagonal phases of ternary Cd
x
Zn
1−x
S at their time of formation with respect to concentration of Cd. [Reproduced with permission from [68] © IOP Publishing. All rights reserved.]
Figure 12.22
HRTEM image revealing high density of planar defects in (a) Cd
0.5
Zn
0.5
S [Reproduced with permission from [68] © IOP Publishing. All rights reserved.] and (b) distorted lattice planes of cubic (200) of Cd
0
.
8
Zn
0
.
2
S forming intrinsic, extrinsic and twin faults. [Reproduced with permission from Elsevier.]
Figure 12.23
(a) Variation of BG as a function concentration of Zn and (b) change in color with increasing concentration of Cd in Cd
x
Zn
1−x
S. [Reproduced with permission from [68] © IOP Publishing. All rights reserved.]
Chapter 13
Figure 13.1
X-ray fluorescent screen.
Figure 13.2
Emission spectrum of X-ray imaging Gd
2
O
2
S: Tb
3+
phosphor [after Ref. 28].
Figure 13.3
Emission spectrum of the blue-emitting (ZnS: Ag) phosphor [after Ref. 29].
Figure 13.4
Emission spectrum of [ZnS: Ag + (Zn, Cd)S: Cu, Al] phosphor [after Ref. 29].
Figure 13.5
Emission spectrum of the ZnS: Cu, Al phosphor [after Ref. 29].
Figure 13.6
(a) Emission spectrum of the Y
2
O
2
S: Eu
3+
phosphor [after Ref. 30]. (b) Excitation spectrum of Y
2
O
2
S: Eu
3+
phosphor [after Ref. 30].
Figure 13.7
(a) Emission spectrum of BaMgAl
10
O
17
: Eu
2+
phosphor [after Ref. 31]. (b) Excitation spectrum of BaMgAl
10
O
17
: Eu
2+
phosphor [after Ref. 31].
Figure 13.8
(a) Emission spectrum of Zn2SiO4: Mn
2+
[after Ref. 32]. (b) Excitation spectrum of Zn2SiO4: Mn
2+
[after Ref. 32].
Figure 13.9
(a) Emission spectrum of [(Y, Gd)BO
3
: Eu
3+
] phosphor [after Ref. 33]. (b) Excitation spectrum of [(Y, Gd)BO
3
: Eu
3+
] phosphor [after Ref. 33].
Figure 13.10
Color LEDs emitting in the blue, green, and red.
Figure 13.11
(I) Emission spectrum of the Halophosphate phosphor [after Ref. 40]. (II) Excitation spectrum of Sb
3+
emission (a), and that of Mn
2+
emission (b), of the phosphor [after Ref. 40].
Figure 13.12
(a) Emission spectrum of [(Sr, Ba, Ca,)
10
(PO
4
)
g
Cl
2
: Eu
2+
] [after Ref. 12]. (b) Excitation spectrum of [(Sr, Ba, Ca,)
10
(PO
4
)
g
Cl
2
: Eu
2+
] [after Ref. 12].
Figure 13.13
(a) Emission spectrum of the LaPO4: Ce
3+
, Tb
3+
[after Ref. 12]. (b) Excitation spectrum of LaPO
4
: Ce
3+
, Tb
3+
[after Ref. 12].
Figure 13.14
(a) Emission spectrum of Y
2
O
3
: Eu
3+
red phosphor[after Ref. 12]. (b) Excitation spectrum of Y
2
O
3
: Eu
3+
red phosphor [after Ref. 12].
Figure 13.15
(a) Emission spectrum of YAG: Ce
3
phosphor [after Ref. 44]. (b) Excitation spectrum of YAG: Ce
3
phosphor [after Ref. 44].
Figure 13.16
Spectrum of the lamp made by coating a blue LED with YAG: Ce
3
phosphor [after Ref. 41].
Figure 13.17
(a) Emission and excitation spectra of BaAl
2
O
4
: Eu
2+
LED phosphor [after Ref. 47]. (b) Emission spectrum of the lamp made by coating the phosphor on a 480 nm blue LED. Inset: The lamp [after Ref. 47].
Figure 13.18
Photo physical scheme of the ESA and ESET.
Figure 13.19
(a) UC emission spectrum of a sample of NaYF
4
: Yb
3+
, Tm
3+
under
λ
exci
. = 985 nm. Inset: 800 nm emission of a NaYF
4
Yb
3+
, Tm
3+
dispersed solution. (b) Scheme of a set up for diagnosis of affected biological cells/tissues inside a living body with the help of UC nanoparticles.
Figure 13.20
Upconversion emission spectrum of a (Er
3+
+Yb
3+
) co-doped barium fluorotellurite glass under 980 nm excitation. Inset: strong green upconversion emission of Er
3+
under 60 mw laser [after Ref. 16].
Figure 13.21
Log–log plots of different UC luminescence of Er
3+
vs. laser power [after Ref. 16].
Figure 13.22
UC luminescence spectrum of the (Ho
3+
, Tm
3+
, Yb3
+
) – tri-doped fluorolead germanate glass ceramic under 975 nm laser excitation. Inset: white light of the mixed blue, green and red emissions [after Ref. 58].
Figure 13.23
(a) Cavity of a LASER source. (b) Coherent emission. (c) Amplified beam.
Figure 13.24
(a and b) Energy level schemes normally observed in the process of laser action of an emiter.
Figure 13.25
Cavity configuration of a solid-state laser.
Figure 13.26
(a) Emission bands/lines of some of the transition metal ions which are proved potential for efficient laser action [after Ref. 66]. (b) Emission lines of some of the of rare earth ions potential for efficient laser action [after Ref. 66].
Figure 13.27
(a) Nd
3+
-doped single crystals. (b) A sample of polished Nd
3+
-doped laser glass rod.
Figure 13.28
Plot of average output power vs. average input pump power of a Nd:YAG single crystal rod resonator (Nd
3+
-concentration = 1.1 at.%) [after Ref. 67].
Figure 13.29
Picture of a Yb
3+
-doped YAG crystal <111> grown by Czochralski method [after Ref. 66].
Figure 13.30
Absorption (a) and emission cross-section (b) spectra of Ho
3+
of the glass [after Ref. 9].
Figure 13.31
Gain spectrum of the
5
I
7
→
5
I
8
NIR emission of Ho
3+
of the glass [after Ref. 9].
Chapter 14
Figure 14.1
Jablonski energy diagram showing mechanism of luminescence.
Figure 14.2
Schematic cross-section of a typical mono-layer OLED.
Figure 14.3
Cross-section of a typical double-layer OLED.
Figure 14.4
Multilayer device structure.
Figure 14.5
Basic operation of LED.
Figure 14.6
Working of OLED.
Figure 14.7
A schematic diagram representing the emission of light in OLEDs.
Figure 14.8
Full color display having primary colors.