Abstract
AlGaN-based light emitting diodes (LEDs) are expected to be the next-generation ultraviolet light (UV) sources. With the aim of achieving AlGaN-based UV-LEDs comparable to conventional blue and red LEDs, we have investigated regular epitaxial growth, the fabrication of uniform and abrupt heterointerfaces, the optical characteristics of AlGaN-based quantum structures, the validity of band engineering, p-n junction designs, radiative recombination, and light extraction. Efficient and transparent UV-LEDs grown on a high-quality AlNtemplate layer on a sapphire substrate have been fabricated. We also discuss the potential of bulk AlN substrate.
