Development of GaN-Based UV LEDs Challenges and Emerging Solutions

Abstract

Gallium nitride (GaN) and its related alloys, particularly aluminum gallium nitride (AlGaN), have emerged as promising materials for deep ultraviolet light-emitting diodes (DUV LEDs) due to their wide bandgap properties and solid-state emission advantages. These devices show broad application potential in areas such as water purification, biological sterilization, and medical diagnostics. However, DUV LEDs currently face significant challenges in terms of external quantum efficiency (EQE), thermal management, and device reliability. This review systematically summarizes the key limitations that hinder the performance of AlGaN-based DUV LEDs, including difficulties in achieving efficient p-type doping in high-Al-content materials, poor carrier injection efficiency, high thermal resistance, and high defect densities. In response to these bottlenecks, various state-of-the-art strategies aimed at improving both internal and external quantum efficiency are discussed, such as quantum well structure optimization, polarization-engineered tunnel junctions, crystalline quality enhancement, interface band engineering, and advanced light extraction designs. Furthermore, the review highlights critical approaches for reducing thermal resistance and enhancing device reliability, including the use of high thermal conductivity substrates, advanced packaging technologies, and thermal interface materials. Overall, the advancement of AlGaN-based DUV LEDs relies on coordinated innovations in materials, device architecture, and system-level integration to realize high-efficiency, high-reliability performance.