Effect of threading strain from the interface between P-GaN and an annealed ITO transparent conducting layer to InGaN/GaN multiple quantum wells

Abstract The effect threading strain from the interface between P-GaN and an Indium Tin Oxide (ITO) layer to InGaN/GaN multiple quantum wells (MQWs) is determined using high resolution transmission electron microscopy (HRTEM) for geometric phase analysis (GPA). The various defects occurs due to threading strain released from the interface to MQWs, which should induce crystallographic defects and have a significant effect on the electronic structure of the device. The current-voltage characteristics and life tests for GaN-based LEDs are studied. Compared with other treated interfaces, there is less strain in MQWs after thermal treatment at 580 °C for 10 min, which gives a minimum forward voltage for LEDs of 2.95 V and a maximum light output power for LEDs of 177.51 mW at 125 mA. The GPA analysis shows that a lower strain enhances the performance of GaN-based LEDs with an ITO contact layer.