(Invited) Deep Ultraviolet Light Emitting Diodes: Physics, Performance, and Applications

Abstract

The key factor for developing deep UV LEDs is material’s quality of nitride epitaxial films. It could be dramatically improved by using novel MEMOCVD® technique. Using very narrow quantum wells (QWs) and energy band gap engineering in deep UV LEDs improves overlap between electron and hole wave functions and increases the Internal Quantum Efficiency (IQE) and External Quantum Efficiency (EQE). A novel transparent and reflecting top contact further boosts IQE and EQE and increases the power output and high external quantum efficiency of our Deep UV LEDs. Research is now under way to use these devices for improving quality and extending storage time of fruits and vegetables. Other applications include water and air purification, sterilization, biological threat identification, applications in medicine, biology, industrial processes, defense, and homeland security.