Wavelength-Tunable Waveguide Emissions from Electrically Driven Single ZnO/ZnO:Ga Superlattice Microwires

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Superlattices with periodic crystalline layers offer versatile control over electronic and photonic properties.
• One-dimensional photon crystals are crucial for modulating light propagation and optical characteristics.

Purpose of the Study:

• To synthesize ZnO/ZnO:Ga superlattice microwires (MWs).
• To investigate wavelength-tunable multipeak emissions from these MWs.
• To explore modulation of emission characteristics using gold (Au) nanoparticle decoration and exciton-polariton emission.

Main Methods:

• Synthesis of individual ZnO/ZnO:Ga superlattice microwires.
• Construction of fluorescent emitters using single superlattice MWs.
• Decoration with Au quasiparticle film and Au nanoparticles.
• Fabrication of heterojunction diodes with ZnO/ZnO:Ga MWs and p-GaN.

Main Results:

• Achieved wavelength-tunable multipeak emissions from UV to visible regions (518–562 nm).
• Au decoration induced red shifts and splitting of emission peaks.
• Demonstrated electrically pumped exciton-polariton emission in the blue-UV range.
• Au nanoparticles enhanced output efficiencies, blue-shifted dominant wavelengths, and narrowed spectral linewidths.
• Identified coupled optical microcavities along the wire axis as the origin of multipeak emissions.

Conclusions:

• ZnO/ZnO:Ga superlattice MWs provide a platform for multicolor emitters.
• These MWs are suitable for developing low-threshold exciton-polariton diodes and lasers.
• The findings offer potential for advanced optoelectronic devices.