Numerical analysis of the compositional graded quaternary barrier AlGaN-based ultraviolet-C light-emitting diode

Abstract

The compositional graded quaternary barriers (GQBs) instead of ternary/conventional quantum barriers (QBs) have been used to numerically enhance the efficiency of AlGaN-based ultraviolet light-emitting diode (LED). The performance of LED with GQBs is examined through carrier concentrations, energy band diagrams, radiative recombination, electron and hole flux, internal quantum efficiency (IQE), and emission spectrum. As a function of the operating current density, a considerable reduction in efficiency droop is observed in the device with composition-graded quaternary barriers as compared to the conventional structure. The efficiency droop in case of a conventional LED is ~77% which decreased to ~33% in case of the proposed structure. Moreover, the concentration of electrons and holes across the active region in case of the proposed structure is increased to ~156% and ~44%, respectively.