Contents1 Physics of ni-Nitnde Light-Emitting Diodes 11.1 History of III-Nitride LEDs 11.2 Mechanisms of Di-Nitride LEDs 21.3 Radiative Recombination and Non-radiative Recombination 41.4 Internal Quantum Efficiency 51.5 Light Extraction Efficiency and External Quantum Efficiency 9References 102 Epitaxial Growth of III-Nitride LEDs 132.1 III-Nitride Blue LEDs 132.2 III-Nitride Green LEDs 192.2.1 InGaN/GaN Superlattice 192.2.2 Stacked GaN/AIN Last Quantum Barrier 362.3 III-Nitride Ultraviolet LEDs 412.3.1 Sputtered AIN Nucleation Layer 412.3.2 Effect of PSS onUYLED 572.3.3 Patterned Sapphire with Silica Array 612.3.4 Isoelectronic Doping 672.3.5 InAIGaN/AIGaN Electron Blocking Layer 742.3.6 Graded Al-Content AlGaN Insertion Layer 78Referencces 823 High-Efficiency Top-Emitting III-Nitride LEDs 913.1 Light Extraction Microstructure 913.1.1 PSS and Patterned ITO 913.1.2 Double Layer ITO 963.1.3 3D Patterned ITO and Wavy Sidewalls 993.1.4 Roughened Sidewalls 1023.1.5 Air Voids Structure 1073.2 Current Blocking Layer 1123.2.1 SiO2 Current Blocking Layer 1123.2.2 Patterned Current Blocking Layer 1173.2.3 Reflective Current Blocking Layer 1223.3 Back Reflector 1253.4 Low Optical Loss Electrode Structure 1353.5 Ni/Au Wire Grid Transparent Conductive Electrodes 142Referencces 1474.1 Via-Hole-Based Two-Level Metallization Electrodes 1514.2 Dielectric DBR 1584.3 Comparison of Flip-Chip LEDs and Top-Emitting LEDs 1614.4 Ag/TiW, Ni/Ag and ITO/DBR Ohmic Contacts 1644.5 High-Power Flip-Chip LEDs 1754.6 Double-Layer Electrode and Hybrid Reflector 1804.7 Mini/Micro-LED 1844.7.1 Prism-Structured Sidewall of Mini-LED 1844.7.2 Light Extraction Analysis of Micro-LED 186Referencces 1905 High Voltage and Vertical LEDs 1935.1 Direct Current High Voltage LED 1935.2 Alternating Current High Voltage LED 1995.3 Comparison of DC-HV LED and AC-HV LED 2015.4 Vertical LEDs 203References 2156 Device Reliability and Measurement 2176.1 Influence of Dislocation Density on Device Reliability 2176.2 Forward Leakage Current 2196.3 Reverse Leakage Current 2226.4 Pad Luster Consistency 2256.5 Transient Measurement of LED Characteristic Parameters References 230