Promoted Current Injection in GaInN/GaN Multi-Quantum Nanowire-Based LEDs Coated With AZO Using Atomic Layer...

GaInN/GaN multi-quantum shell (MQS) nanowires (NWs) are promising candidates for high-efficiency microscale and nanoscale light-emitting diodes (LEDs), offering reduced efficiency losses from the quantum-confined Stark effect and nonradiative recombination. However, the three-dimensional NW geometry complicates electrode deposition, leading to nonuniform current injection and emission variations. Here, we demonstrated enhanced current injection in NW-LEDs using a conformal aluminum-doped zinc oxide (AZO) film deposited via atomic layer deposition (ALD). Finite element simulations revealed that extended p-type electrode coverage can promote both axial and lateral current injection from the sidewalls, enhancing radiative recombination across the (0001), (1 $\bar{1}$ 01), and (10 $\bar{1}$ 0) planes. We systematically compared device fabrication processes, transparent electrode morphologies, and optoelectronic performance using AZO and indium tin oxide (ITO) electrodes deposited via ALD and sputtering. Cross-sectional morphology characterization confirmed minimal thickness variation of ALD-deposited AZO, enabling uniform sidewall coverage and deposition in the regions between NWs, which is challenging for sputtered ITO. Uniform AZO deposition by ALD improved light output by a factor of 1.2 at an injection current of 30 mA. These results demonstrate that conformal AZO enables uniform transparent electrodes, promotes efficient current injection throughout the NWs, and represents a promising alternative to ITO in NW-LEDs.