Introduction to Light Emitting Diode Technology and Applications

by Held; Gilbert

• ISBN13: 9781420076622
• ISBN10: 1420076620
• Edition: 1st
• Format: Hardcover
• Copyright: 2008-12-22
• Publisher: Auerbach Public

Summary

Recent improvements in LED technology have made them as ubiquitous as cell phones. In fact, LEDs light up almost all cell phone screens. The technology's myriad applications and low energy use have made it nearly impossible to get through daily chores without coming in contact with LEDs. Probable advances include the increased ability of the technology to support more efficient lighting and enhanced communications. With balanced coverage of the basics and future developments, Introduction to Light Emitting Diode Technology and Applications takes you on a tour of the LED evolution.

Table of Contents

Preface	p. xiii
Acknowledgments	p. xv
Introduction to LEDs	p. 1
Basic Operation	p. 1
The p-n Junction	p. 1
No Applied Voltage	p. 2
Applying Forward-Bias	p. 2
Applying Reverse-Bias	p. 3
LED Operation	p. 4
Similarity to a Diode	p. 4
Crossing the Barrier	p. 4
LED Evolution	p. 4
The First LED	p. 5
Doping Materials	p. 5
Voltage and Current Requirements	p. 8
Manufacture of LEDs	p. 8
Parallel and Series Operations	p. 10
Current Limitation Considerations	p. 12
Types, Functions, and Applications	p. 18
Types of LEDs	p. 18
Physical Characteristics	p. 18
Colors	p. 20
Flashing LEDs	p. 21
LED Displays	p. 22
Applications	p. 23
Lighting	p. 23
Other Applications	p. 24
Fundamentals of Light	p. 27
Properties of Light	p. 27
Speed of Light	p. 27
Photons	p. 28
Planck's Constant	p. 28
Frequency, Energy, and Light	p. 29
Frequency and Wavelength	p. 29
Frequency	p. 30
Frequency of Waves	p. 30
The Electromagnetic Spectrum	p. 30
Spectral Power Distribution	p. 31
Incandescent Light	p. 32
Fluorescent Light	p. 32
The CIE Color System	p. 33
The Maxwell Triangle	p. 33
Overview	p. 33
Limitations	p. 34
The Spectral Locus	p. 34
CIE Theoretical Primaries	p. 35
CIE Chromaticity Chart	p. 35
LED Light	p. 36
Comparing LEDs	p. 37
White Light Creation Using LEDs	p. 37
White Light Creation by Mixing Colors	p. 37
White Light Creation Using Phosphor	p. 37
Intensity of an LED	p. 40
Candlepower	p. 40
The Candela	p. 41
On-Axis Measurement	p. 41
Theta One-Half Point	p. 42
Current and Voltage Considerations	p. 43
Lumens, Candelas, Millicandelas, and Other Terms	p. 43
Lumens	p. 44
Lumens per Watt and Lux	p. 45
Watt Dissipation	p. 45
Steradian	p. 46
Luminous Energy	p. 47
Illuminance	p. 48
Lighting Efficiency	p. 48
Color Temperature	p. 49
Representative Lighting Color Temperature	p. 49
LED White Light Creation	p. 50
Wavelength Conversion	p. 50
Color Mixing	p. 51
Homoepitaxial ZnSe	p. 51
LEDs Examined	p. 53
P-N Junction Operation	p. 53
Semiconductor Material	p. 54
Basic Concepts of Atoms	p. 54
Electrical Charge	p. 55
Band Theory	p. 55
Energy Bands	p. 55
Conduction and Valence Bands of Conductors, Semiconductors, and Insulators	p. 56
Equilibrium	p. 57
Depletion Region Operation	p. 58
Bias Effect	p. 59
Diodes and LEDs	p. 60
LED Operation	p. 60
Color of the Light Emitted by an LED	p. 61
Light Production	p. 62
Organic Light-Emitting Diodes	p. 63
Overview	p. 63
Comparing Technologies	p. 64
LCDs versus OLEDs	p. 64
Types of Displays	p. 65
PMOLED	p. 65
AMOLED	p. 66
Limitations of OLEDs	p. 68
Lifetime of OLEDs	p. 68
Fabrication and Ramp-Up Cost	p. 69
OLED TV	p. 69
Other Markets	p. 71
LED Drivers	p. 72
Rationale for Use	p. 73
Using PWM	p. 74
Driver Definition	p. 75
Driver Connection	p. 75
Types of Drivers	p. 75
Boost LED Drivers	p. 76
Step-Down LED Drivers	p. 76
Buck-Boost LED Drivers	p. 77
Multitopology Driver	p. 77
Pump LED Driver	p. 77
Summary	p. 78
LEDs and Lighting	p. 79
Rationale	p. 80
Incandescent Lightbulbs	p. 80
Economics of Use	p. 81
Compact Fluorescent Lightbulbs	p. 82
Cost Reduction	p. 82
Utility Subsidization	p. 83
The Federal 2007 Energy Bill	p. 84
Economics of Use	p. 84
Disposal Problems	p. 85
LED Lightbulbs	p. 86
Purchase Considerations	p. 86
Quality of Light	p. 88
High-Brightness (HB) LEDs	p. 90
Overview	p. 91
Metal-Organic Chemical-Vapor Deposition System	p. 91
Initially Developed HB LEDs	p. 92
Utilization	p. 92
Fabrication Forms	p. 93
ac versus dc Power	p. 93
Seoul Semiconductors	p. 94
Lynk Labs	p. 95
HB-LED Output	p. 96
Energy Star Program Developments	p. 97
Outdoor Lighting Developments	p. 98
Cities Discovering LEDs	p. 99
Lighting Science Group	p. 100
OSRAM Opto Semiconductors	p. 101
LEDs in Communications	p. 103
Remote Control and Infrared LEDs	p. 103
Overview	p. 104
The Infrared Region	p. 104
Rationale for Use	p. 104
Frequency and Wavelength	p. 104
Evolution in the Use of IR	p. 106
IR Remote Operation: IR Port	p. 106
Types of IR Devices	p. 107
Emitters	p. 107
Detector	p. 107
Photo Interrupter	p. 107
Photo Reflector	p. 108
IR Transceiver	p. 108
TV Remote Control	p. 109
The IR Signal	p. 109
ASK Modulation	p. 109
FSK Modulation	p. 110
Interference	p. 110
Inside a TV Remote Control	p. 111
Operation	p. 111
Printed Circuit Board	p. 112
Remote Control LEDs	p. 113
Wavelengths and Fabrication	p. 113
Technical Details	p. 113
Cost	p. 114
IR Detection with IR Photodiode	p. 114
Overview	p. 114
Modes	p. 115
Composition	p. 116
Packaging	p. 116
Operation	p. 117
Selecting a Resistor	p. 117
Limiting the Value of the Resistor	p. 118
Maximum Resistance	p. 118
Ethernet Networking	p. 119
Fiber-Optic Cable	p. 120
Decibels Power Measurements	p. 120
Single versus Dual Cables	p. 121
Cable Composition	p. 122
Types of Fiber Cable	p. 122
Fiber and Wavelength	p. 123
FOIRL and 10BASE-F	p. 124
Overview	p. 125
Optical Transceiver	p. 125
The Fiber Hub	p. 125
Fiber Adapter	p. 126
Wire and Fiber Distance Limitations	p. 126
10BASE-F	p. 127
10BASE-FL	p. 127
10BASE-FB	p. 129
10BASE-FP	p. 129
Optical Media Support	p. 129
Fast Ethernet	p. 130
100BASE-FX	p. 130
100BASE-SX	p. 130
Gigabit Ethernet	p. 131
Comparing LEDs and Laser Diodes	p. 133
The Laser Diode	p. 133
Emission of Coherent Light by Laser Diodes	p. 134
The Quantum Process	p. 134
Use of Mirrors	p. 136
Reviewing LED and Laser Diode Operations	p. 137
Evolution of Laser Diodes	p. 137
Types of Laser Diodes	p. 138
Edge-Emitting Laser Diode	p. 138
Double Heterostructure Laser	p. 140
Quantum Well Laser	p. 140
Vertical-Cavity Surface-Emitting Laser (VCSEL)	p. 141
Trade-offs between Various Laser Diodes	p. 143
Vertical External Cavity Surface-Emitting Laser	p. 143
Comparing Laser Diodes and LEDs	p. 143
Comparing Operational Characteristics	p. 143
Performance Characteristics	p. 144
Speed	p. 144
Peak Wavelength	p. 145
Power Coupling	p. 145
Spectral Width	p. 145
Emission Pattern	p. 145
Linearity	p. 146
Luminous Efficacy	p. 147
Drivers	p. 147
Safety	p. 148
Applications	p. 148
Commercial Applications	p. 149
Data Communications	p. 150
Dental Applications	p. 151
Illumination Application	p. 151
Medical Application	p. 151
Military Applications	p. 151
The Evolving LED	p. 153
Lighting	p. 153
Increasing LED Density	p. 154
Light Output per LED	p. 154
Communications	p. 157
Organic LEDs	p. 158
Display Utilization	p. 158
Advantages	p. 158
Current Deficiencies	p. 159
Lighting	p. 160
Index	p. 161
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