Continuous-wave electrically injected GaN-on-Si microdisk laser diodes.

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Silicon photonics requires efficient, room-temperature, electrically driven on-chip light sources.
• Gallium Nitride (GaN)-based microdisk lasers on Silicon (Si) are promising for compact integrated photonic circuits.

Purpose of the Study:

• To develop a continuous-wave, electrically pumped Indium Gallium Nitride (InGaN)-based microdisk laser grown on Si operating at room temperature.
• To reduce the operational voltage and threshold current of GaN-on-Si microdisk lasers.

Main Methods:

• Suppression of unintentional carbon impurity incorporation in the p-type Aluminum Gallium Nitride (AlGaN) cladding layer.
• Shrinking the microdisk laser radius to 8 µm to minimize thermal power.
• Optimization of material growth and device fabrication for GaN-on-Si heterostructures.

Main Results:

• Significant reduction in the operation voltage and threshold current of the GaN-on-Si microdisk laser.
• Effective reduction of the overall junction temperature of the microdisk laser.
• Demonstration of the first continuous-wave (CW) electrically pumped InGaN-based microdisk laser grown on Si at room temperature.

Conclusions:

• The developed GaN-on-Si microdisk laser addresses the long-standing need for on-chip light sources in silicon photonics.
• Reduced carbon impurities and smaller device dimensions are key to achieving efficient room-temperature operation.
• This work paves the way for advanced integrated photonic devices and systems leveraging silicon platforms.