Improved Ultraviolet-B Light-Emitting Diodes with Graded All Quaternary Layers in the Active Region

Abstract

We employ quaternary graded AlInGaN layers numerically in the active region to study the effect on the optoelectronic properties of AlGaN-based ultraviolet light-emitting diodes (UV LEDs). We evaluated the device performance by analyzing carriers concentrations, carrier flux, radiative recombination rate, energy band diagrams and internal quantum efficiency (IQE). We compare the results with the reference device structure and found that the device with quaternary graded AlInGaN layers has high peak efficiency as well as low efficiency droop.