Electrically pumped InGaAs/GaAs quantum well microdisk lasers directly grown on Si(100) with Ge/GaAs buffer.

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Monolithic integration of III-V optoelectronics on silicon is crucial for advanced photonic circuits.
• Previous efforts faced challenges in achieving efficient and stable laser performance on silicon.

Purpose of the Study:

• To demonstrate the first electrically-pumped quantum well microdisk lasers monolithically grown on a silicon substrate.
• To investigate the performance characteristics of these novel silicon-based lasers at room temperature.

Main Methods:

• Epitaxial growth of III-V laser structures on (001)-oriented silicon using Metalorganic Chemical Vapor Deposition (MOCVD) and Molecular Beam Epitaxy (MBE) for a germanium buffer layer.
• Fabrication and testing of InGaAs/GaAs quantum well microdisk lasers with varying diameters (23, 27, 31 µm).
• Room-temperature characterization under pulsed electrical injection to determine threshold current density and lasing spectrum.

Main Results:

• Successful monolithic deposition of quantum well microdisk lasers on a silicon substrate.
• Achieved room-temperature lasing in microlasers with diameters of 23, 27, and 31 µm.
• Minimal threshold current density of 28 kA/cm² and predominantly single-mode lasing with a linewidth as narrow as 35 pm were recorded.

Conclusions:

• This work establishes a significant advancement in integrating high-performance lasers onto silicon platforms.
• The demonstrated microdisk lasers show promising potential for applications in silicon photonics and integrated optoelectronics.
• Further optimization could lead to lower threshold currents and improved device efficiency for practical applications.