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Updated: May 11, 2026
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Optimized Fabrication Procedure for High-Quality Graphene-based Moiré Superlattice Devices
Published on: July 11, 2025
Epitaxial GaN microdisk lasers grown on graphene microdots.
Hyeonjun Baek1, Chul-Ho Lee, Kunook Chung
1National Creative Research Initiative Center for Semiconductor Nanostructures and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
Nano Letters
|May 15, 2013
Summary
Researchers developed a method for growing high-quality gallium nitride (GaN) microdisks on silicon using graphene nucleation layers. This breakthrough enables optoelectronic devices on unconventional substrates, demonstrating room-temperature lasing.
Area of Science:
- Materials Science
- Optoelectronics
- Semiconductor Physics
Background:
- Direct epitaxial growth of semiconductors on matched substrates is standard for optoelectronics.
- Emerging applications require growth on unconventional substrates like silicon, glass, and plastics.
- Lattice and thermal expansion mismatches hinder high-quality film growth on these diverse substrates.
Purpose of the Study:
- To develop a method for fabricating high-quality gallium nitride (GaN) microdisks on amorphous silicon oxide layers.
- To enable monolithic fabrication of optoelectronic devices on unconventional substrates.
- To investigate the potential for lasing in GaN microdisks grown via this novel method.
Main Methods:
- Utilized micropatterned graphene films as a nucleation layer on amorphous silicon oxide on silicon.
- Employed epitaxial lateral overgrowth (ELO) on graphene dots with intermediate zinc oxide (ZnO) nanowalls.
- Grew highly crystalline GaN microdisks with hexagonal facets.
Main Results:
- Successfully grew high-quality, crystalline GaN microdisks on amorphous silicon oxide using graphene nucleation.
- Observed whispering-gallery-mode (WGM) lasing from the GaN microdisk.
- Achieved a high Q-factor of 1200 for the lasing microdisk at room temperature.
Conclusions:
- Graphene nucleation layers enable high-quality GaN growth on unconventional amorphous substrates.
- The developed method facilitates monolithic integration of optoelectronic devices on silicon.
- Demonstrated room-temperature WGM lasing in GaN microdisks, paving the way for advanced photonic applications.
