Improved internal quantum efficiency of GaN-based light emitting diodes using p-AlGaN trench in multi-quantum well

In this work, a novel structure for GaN-based LED featuring p-AlGaN trench in the MQW is proposed. Through a numerical simulation, it is confirmed that the proposed structure shows much uniform hole distribution in the MQW than that of the conventional structure, because holes are injected efficiently into the MQW along the p-AlGaN trench. We also confirmed that efficiency droop is reduced and the IQE is improved about 12% when 1 A current flows because of the improved hole distribution. In order to optimize the physical parameters of the p-AlGaN trench, the IQE and the operating voltage are analyzed when the width of the p-AlGaN trench and the distance between the p-AlGaN trenches are changed. In addition, a simple fabrication process for manufacturing the proposed structure is also suggested.