Characterizations of strain and defect free GaN nanorods on Si(111) substrates

TL;DR

This study demonstrates that GaN nanorods grown on Si(111) substrates are free of strain and defects, with their supporting matrix absorbing strains, and highlights their potential for optoelectronic applications due to photo-induced electron effects.

Contribution

The paper provides a detailed characterization showing strain- and defect-free GaN nanorods on Si(111), emphasizing the role of the supporting matrix and potential device applications.

Findings

Nanorods are strain- and defect-free as shown by micro Raman spectroscopy.

The supporting matrix absorbs strains and defects, enabling perfect nanorod growth.

Photo-excitation increases non-equilibrium electrons, useful for optoelectronic devices.

Abstract

GaN-nanorods grown on Si(111) substrates are found strain- and defect-free as characterized by micro Raman spectroscopy, secondary electron (SE) and cathode-luminescence (CL) imaging. The matrix supporting the nanorods bears the brunt of all strains, strain-relaxations, and defect generations, giving the nanorods an ideal environment to grow to perfection. Photo-excitations by the Raman laser source and electron irradiation during CL imaging lead to an increase of non-equilibrium electrons, suggesting an effective approach to photo-emitting or field emitting device applications. The nanorods, largely isolated from but perfectly aligned with the sustaining matrix, are grown in excellent epitaxy with the Si substrates.