Improved Uniform Current Injection into Core-Shell-Type GaInN Nanowire Light-Emitting Diodes by Optimizing Growth Condition and Indium-Tin-Oxide Deposition

The aim of this research is to realize high-efficiency light-emitting diodes (LEDs) with a 3D core-shell GaN nanowire. This article describes the growth of 3D core-shell GaN nanowires, the formation of indium tin oxide (ITO) around the p-GaN outer shell of the nanowires, and the characteristics of the fabricated nanowire-LED (NW-LED). The structural properties of the n-GaN core, GaInN/GaN multiquantum shell (MQS), p-GaN outer shell, and ITO electrode are investigated by scanning electron microscopy and scanning transmission electron microscopy. In addition, the optical and electrical characteristics of the NW-LEDs are evaluated. The findings show that the grown n-GaN cores have a uniform height and diameter, the MQS is defect-free with a uniform film thickness, and p-GaN outer shells with a uniform thickness are grown on both the m- and c-planes. Consequently, a NW-LED that emits light from the entire chip area is successfully realized by depositing an ITO electrode that covers the p-GaN outer shells with a uniform film thickness.