Blue-green emitting microdisks using low-temperature-grown ZnO on patterned silicon substrates.
Optics Express
|October 24, 2013
Summary
Researchers developed high-quality zinc oxide (ZnO) resonators for photonic devices using a novel low-temperature growth method. These resonators exhibit exceptional whispering gallery modes (WGMs) with high quality factors, advancing ZnO-based optoelectronics.
Area of Science:
- Materials Science
- Optoelectronics
- Nanotechnology
Background:
- Zinc oxide (ZnO) is a promising material for photonic devices due to its bright emission properties.
- Fabrication of ZnO-based devices is challenging due to the absence of selective etching techniques for epitaxial growth.
Purpose of the Study:
- To develop a method for fabricating high-quality ZnO resonators.
- To investigate the optical properties of ZnO resonators created using a low-temperature growth process.
Main Methods:
- Low-temperature growth of ZnO on pre-patterned silicon dioxide (SiO₂) microdisks (MDs).
- Characterization of whispering gallery modes (WGMs) and quality factors.
- Deposition of SiO₂ capping layers to enhance light coupling.
Main Results:
- High-quality ZnO resonators were successfully created.
- Observed WGMs in the blue-green spectrum with quality factors exceeding Q = 3500.
- Demonstrated enhanced spontaneous emission coupling into MDs with SiO₂ capping, showing sharp WGMs up to N = 3.
Conclusions:
- The low-temperature growth process on pre-patterned SiO₂ MDs enables high-quality ZnO resonator fabrication.
- The achieved quality factors are among the highest reported for ZnO resonators.
- SiO₂ capping layers effectively enhance light-matter interaction in ZnO microdisk resonators.
