This book covers the industrial aspects of light-emitting diodes (LEDs) for solid-state lighting (SSL). The author targets his approach primarily to industrial engineers, in order to guide them in the LED industry. The coverage is highly-applied and based on author’s 32 years of experience in the LED industry and academia. The book starts by addressing the needs that new engineers encounter in an LED company, e.g., characterization, manufacturing, and applications. Later chapters introduce deeper science for more experienced engineers and academic readers. As a result, this book can benefit LED engineers throughout their career.
Author(s): Hisashi Masui
Series: Synthesis Lectures on Materials and Optics
Publisher: Springer
Year: 2023
Language: English
Pages: 211
City: Cham
Foreword
Preface
Contents
Acronyms
1 Introduction
1.1 Definition and the Range of LED
1.2 LED in Lighting History
1.3 Safety Precautions
2 Characterization Techniques
2.1 Purpose of Characterization
2.2 Characterization Apparatus
2.3 Data Interpretation
2.4 Efficiency Breakdown
2.5 Effect of Encapsulation on Light Output
2.6 Optical Characterization, Geometry Involved
2.7 Electrical Characterization
2.8 Testing and Characterization in Wafer and Tile Forms
2.9 Thermal Characterization
2.10 Reliability Tests and Stressing Experiments
2.11 Further Reading
3 Device Architecture and Fabrication
3.1 LED Chip (Die) and Market Segmentation of Products
3.2 Chip Architecture
3.3 LED Wafer Fabrication via Epitaxy
3.4 Functional Device Fabrication
3.5 Down-Converter (Phosphor) Integration and Packaging
3.6 UV-Pump White LEDs
3.7 Stack-Up Tolerance
3.8 Further Reading
4 Semiconductor Crystals and Device Physics
4.1 Semiconductor Materials for LEDs
4.2 Luminescence Mechanism
4.2.1 In Semiconductor Materials
4.2.2 In Device Structures
4.2.3 Crystal Defects in GaN
4.3 Phosphor Materials
4.3.1 Material Types for LED Application
4.3.2 Luminescence Characteristics of Phosphors
4.4 Silicone Encapsulant
4.5 LED as a Diode: Electrical Aspects
4.5.1 Diode Equation
4.5.2 Real LED Devices
4.6 Further Reading
5 Optics
5.1 Light as EM Wave
5.2 TIR Devices
5.3 Reflectance and Transmittance Spectra
5.4 Geometrical Optics
5.5 Fourier Optics
5.5.1 Fourier Transform by Wave Diffraction and Interference
5.5.2 The Use of a Lens
5.6 Electron Optics
5.7 Further Reading
A Eight-Page Introduction to Semiconductor Basics
A.1 Formation of Semiconductor Crystals
A.2 Controlling Electrical Conductivity in a Semiconductor
A.3 The pn Junction and Built-In Potential
A.4 Current Flow: Carrier Transport and Recombination
A.5 Further Reading
Hole Generation and Transport in Mg-Doped GaN
B.1 Thermal Ionization of Mg in GaN
B.2 Current Carried by Holes
Origin of the Turn-On Voltage
C.1 Voltage Aspect: Quantization of Injected Minority-Carrier Concentration
C.2 Current Aspect: Experimental Observation of the Turn-On
Wave-Particle Duality and the Wavefunction
Crystal Momentum and the E–k Diagram
E.1 Electron Wave in a Crystal
E.2 E–k Diagram
Entropy and Thermal Carrier Distribution
F.1 Classical View
F.2 Quantum Mechanical View
E.3 Logarithmic Definition
F.4 Further Reading
Density of States and Quantum Effect
G.1 Computing DOS
G.2 In Low-Dimensional Structures
G.3 Use of the Particle-in-a-Box Problem
G.4 Further Reading
Phonons and Their Role in Electronic Transitions
H.1 Notion of the Phonon
H.2 In Electronic Transitions
H.3 Further Reading
Spontaneous and Piezoelectric Polarization Fields in III-Nitrides
I.1 Spontaneous Polarization Field in GaN
I.2 Polarization Fields in a Strain InGaN QW
The ABC Model for Recombination Dynamics
J.1 Formulation Under High-Injection Approximation
J.2 Curve Fitting of Steady-State Experiments
J.3 Time-Decay Analysis
J.4 Mechanism Assignment and Low Injection Approximation
J.5 Approximation Validity
The Exciton
Organic LEDs
Glossary
