Investigations on deep ultraviolet light-emitting diodes with quaternary AlInGaN streamlined quantum barriers for reducing polarization effect

Abstract The characteristics of AlGaN-based deep ultraviolet light-emitting diodes (UV LEDs) with quaternary AlInGaN streamlined quantum barriers (QBs) are investigated in this paper. The simulated results show that the light output power and the internal quantum efficiency (IQE) of deep UV LEDs with AlInGaN streamlined QBs have been improved obviously, and the efficiency droop effect has been significantly alleviated. After in-depth study, it is shown that quaternary AlInGaN streamlined QBs is designed to reduce the polarization charge density between quantum wells (QWs) and QBs, and relieve band bending. In addition, the streamline barrier can reduce the kinetic energy of injected carriers, and improve the probability of the carriers being bounced back to the quantum wells, so as to enhance the capture of carriers in the quantum wells. As a result, the recombination rate of electron and hole in the QWs is enhanced, the light output power and the IQE are improved, and the efficiency droop effect is alleviated.