Performance of AlGaN/InGaN Multiple Quantum Well LEDs Simulated Using COMSOL

In this work, efficiency droop phenomena which is one of the most significant
challenges faced by GaN-based light emitting diodes (LEDs) is investigated in both
single quantum well (SQW) and multiple quantum well (MQW) LEDs. There are
many mechanisms which are proposed to be responsible for efficiency droop but the
focus of this work is only on electron leakage and current crowding. In order to
address these phenomena, SQW and MQW GaN-based
LEDs is simulated using COMSOL Multiphysics and the performance of the LEDs is
analyzed by plotting the graph of internal quantum efficiency (IQE) against current
density. Based on the graph, it is found out that the efficiency droop worsens when
the number of quantum well (QW) increases. From this observation, it is proposed to
introduce graphene-based transparent conductive electrodes (TCEs) onto the LEDs
surface. Graphene monolayer will spread the current away from the metal pads and
hence reduce the current crowding problem and improve the efficiency droop.