Controlling a nanowire quantum dot band gap using a straining dielectric envelope.

Area of Science:

• Semiconductor Nanostructures
• Quantum Dots
• Materials Science

Background:

• Indium Arsenide Phosphide (InAsP) quantum dots in Indium Phosphide (InP) nanowires are promising for optoelectronic devices.
• Precise control over their emission wavelength is crucial for device tunability and performance.

Purpose of the Study:

• To tune the emission wavelength of InAsP quantum dots in InP nanowires.
• To investigate the impact of strain induced by a SiO(2) envelope on quantum dot optical properties.
• To explore the potential for engineering band gaps in nanowire devices.

Main Methods:

• Deposition of a silicon dioxide (SiO(2)) envelope using plasma-enhanced chemical vapor deposition (PECVD).
• Optical characterization to assess emission wavelength and quality.
• Atomistic empirical tight-binding calculations to model strain effects on quantum dot band structure.

Main Results:

• Achieved a 200 meV tuning range of the emission wavelength without optical quality degradation.
• Demonstrated both red and blue shifts in emission by controlling SiO(2) deposition.
• Calculations provided insights into strain effects on band structure for various quantum dot parameters.

Conclusions:

• A SiO(2) envelope effectively induces controlled strain, enabling precise wavelength tuning of InAsP quantum dots in InP nanowires.
• This strain engineering approach offers unprecedented possibilities for extending the application range of nanowire-based devices.
• The study highlights a viable method for tailoring optoelectronic properties of semiconductor nanowires.