Lateral Ordering of InAs Quantum Dots on Cross-hatch Patterned GaInP

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Lateral ordering of quantum dots (QDs) is crucial for advanced optoelectronic devices.
• Misfit dislocation networks in strained semiconductor layers can influence QD self-assembly.
• Gallium indium phosphide (GaInP) is a relevant material for heterostructures.

Purpose of the Study:

• To investigate the effect of partially relaxed tensile and compressively strained GaInP layers on the lateral ordering of InAs quantum dots.
• To understand the role of misfit dislocations in this ordering process.
• To explore the influence of growth temperature on dislocation type and QD ordering.

Main Methods:

• Growth of strained GaInP layers and InAs quantum dots.
• Characterization using atomic force microscopy (AFM) and scanning electron microscopy (SEM).
• Analysis of strain and dislocations via X-ray reciprocal space mapping (RSM).

Main Results:

• Lateral ordering of InAs QDs was successfully achieved using strained GaInP.
• Compressive GaInP showed QD ordering similar to compressive GaInAs.
• Tensile GaInP exhibited significantly enhanced lateral ordering of InAs QDs.
• The dominant dislocation type in GaInP layers varied with growth temperature.

Conclusions:

• Partially relaxed tensile GaInP layers are highly effective for promoting lateral ordering of InAs QDs.
• The choice of strain type in GaInP significantly impacts QD ordering.
• Growth temperature is a critical parameter for controlling dislocations and QD arrangement in GaInP/InAs systems.