III-nitride core-shell nanorod array on quartz substrates.

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Gallium nitride (GaN) nanostructures are crucial for optoelectronic devices.
• Growing GaN nanorods on amorphous substrates like quartz presents challenges in orientation and control.
• Existing fabrication methods often lack precise control over nanorod dimensions and placement.

Purpose of the Study:

• To develop a method for fabricating near-vertically elongated GaN nanorods on quartz substrates.
• To control the preferred orientation and length of individual GaN nanorods.
• To investigate the structural and optical properties of GaN and InGaN/GaN core-shell nanorods for device applications.

Main Methods:

• Combined molecular beam epitaxy (MBE) for buffer layer growth with pulsed-mode metal-organic chemical vapor deposition (MOCVD) for nanorod elongation.
• Utilized MBE to create an ordered GaN nanograin buffer layer with preferred surface normal orientation.
• Employed selective-area growth via MOCVD for position-controlled fabrication of GaN nanorods.
• Investigated microstructural and optical properties of fabricated nanorods.

Main Results:

• Successfully fabricated near-vertically elongated GaN nanorods on quartz substrates.
• Achieved controlled orientation and length of individual nanorods through the hybrid MBE-MOCVD approach.
• Demonstrated highly crystalline GaN nanorods and InGaN/GaN core-shell structures.
• Observed optical emission properties from the core-shell nanorods.

Conclusions:

• The combined MBE and pulsed-MOCVD technique effectively enables the fabrication of oriented GaN nanorods on amorphous quartz.
• The resulting highly crystalline GaN and InGaN/GaN nanostructures exhibit promising optical properties.
• This fabrication approach demonstrates the feasibility of creating III-nitride nano-optoelectronic devices on non-conventional amorphous substrates.