Spatially and Time-Resolved Carrier Dynamics in Core-Shell InGaN/GaN Multiple-Quantum Wells on GaN Wire

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Time-resolved cathodoluminescence offers high temporal and spatial resolution.
• X-ray excited optical luminescence (XEOL) provides optical spectroscopic information using synchrotron pulses.
• Hard X-ray nanoprobe techniques enable advanced material analysis.

Purpose of the Study:

• To apply time-resolved X-ray microscopy to core-shell InGaN/GaN multiple quantum well heterostructures.
• To investigate carrier dynamics and recombination rates in these nanostructures.
• To explore carrier localization phenomena at the nanoscale.

Main Methods:

• Utilized time-resolved X-ray microscopy with 20 ps time resolution and 80 nm lateral resolution.
• Applied the technique to individual core-shell InGaN/GaN multiple quantum well heterostructures on GaN wires.
• Leveraged X-ray excited optical luminescence (XEOL) phenomenon.

Main Results:

• Identified that m-plane related multiple quantum well states govern carrier dynamics.
• Observed the influence of Indium (In) incorporation on recombination rates.
• Detected carrier localization phenomena at the hexagon wire apex.

Conclusions:

• The study provides insights into carrier dynamics in InGaN/GaN nanostructures.
• Findings support the role of In incorporation and localization in recombination processes.
• Highlights the potential of time-resolved XEOL microscopy for optoelectronic nanodevice research, especially when combined with other methods like X-ray absorption spectroscopy.