Efficiency enhancement of an InGaN light-emitting diode with a u-InGaN/AlInGaN superlattice last quantum barrier

In this study, a new design on last quantum barrier (LQB) is investigated numerically with the purpose of improving the optical performance of InGaN light-emitting diodes (LEDs). Through the analysis of the energy band diagrams, electrostatic fields, carrier concentrations, carrier current densities, and radiative recombination rates, we have got the simulation results that the proposed undoped-InGaN/AlInGaN superlattice (SL) LQB can significantly improve the output power and internal quantum efficiency, which is mainly attributed to the successful improvement in hole injection efficiency and suppression of electron current leakage. Moreover, the efficiency droop of the LEDs is improved slightly by using u-InGaN/AlInGaN SL as last barrier.