AlGaN-based thin-film ultraviolet laser diodes and light-emitting diodes

Abstract Wide bandgap semiconductor aluminum gallium nitride (AlGaN) alloys have been identified as the key materials to build ultraviolet light emitting devices owing to its direct tunable bandgaps from 3.4 to 6.1 eV, covering wide range of ultraviolet spectrum from 360 to 210 nm. In this chapter, we present the recent progress on the development of AlGaN-based thin-film ultraviolet laser diodes as well as the light emitting diodes, including their past, current and future efforts devoted in this exciting field.