Enhanced hole transport in AlGaN deep ultraviolet light-emitting diodes using a double-sided step graded superlattice electron blocking layer

Abstract

In this paper, deep ultraviolet AlGaN light-emitting diodes (LEDs) with a novel double-sided step graded superlattice (DSGS) electron blocking layer (EBL) instead of a conventional EBL have been proposed for ${\sim}{{254}}\;{\rm{nm}}$ wavelength emission. The enhanced carrier transport in the DSGS structure results in reduced electron leakage into the $p$-region, improved hole activation and hole injection, and enhanced output power and external quantum efficiency. The calculations show that output power of the DSGS structure is ${\sim}{3.56}$ times higher and electron leakage is ${\sim}{{12}}$ times lower, compared to the conventional structure. Moreover, the efficiency droop at 60 mA in the DSGS LED was found to be ${\sim}{9.1}\%$, which is ${\sim}{4.5}$ times lower than the regular LED structure.