Suppression of the subband parasitic peak by 1nm i-AlN interlayer in AlGaN deep ultraviolet light-emitting diodes

Abstract

The origin and suppression of the subband parasitic peak in AlGaN deep ultraviolet light-emitting diodes have been studied. The parasitic peak is clarified to come from a p-AlGaN cladding layer and to be related to Mg dopants. By using 1nm i-AlN as an interlayer between the active region and the p-AlGaN cladding layer, this peak is suppressed efficiently. The devices with such an interlayer show improved output power by a factor of 4 at injection current density of 20A∕cm2, except that the series resistance and turn-on voltage are slightly increased.