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 ∼ 254 n m 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 ∼ 3.56 times higher and electron leakage is ∼ 12 times lower, compared to the conventional structure. Moreover, the efficiency droop at 60 mA in the DSGS LED was found to be ∼ 9.1 % , which is ∼ 4.5 times lower than the regular LED structure.