Wurtzite InP microdisks: from epitaxy to room-temperature lasing

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Metastable wurtzite crystal phases offer tunable direct band gaps for high-performance electro-optical devices.
• Synthesizing these materials beyond nanowire dimensions with high quality has been a significant challenge.

Purpose of the Study:

• To explore the epitaxy of wurtzite Indium Phosphide (InP) microdisks and related geometries on an insulator.
• To enable advanced optical applications by overcoming previous size constraints in material synthesis.

Main Methods:

• Utilized a combination of selective area growth of fins and zipper-induced epitaxial lateral overgrowth.
• Enabled co-integration of diverse crystal shapes at precise locations on an insulating substrate.

Main Results:

• Achieved high phase purity and excellent optical quality in the grown wurtzite InP materials, verified by STEM and µ-PL.
• Demonstrated optically pumped lasing at room temperature in microdisks with a low threshold of 365 µJ cm⁻².

Conclusions:

• The developed platform successfully enables the synthesis of high-quality wurtzite InP microdisks and related geometries.
• This approach provides novel geometries for advanced photonic applications, overcoming previous limitations in material quality and size.