Self-assembled flower-like nanostructures of InN and GaN grown by plasma-assisted molecular beam epitaxy
ABSTRACT Nanosized hexagonal InN flower-like structures were fabricated by droplet epitaxy on GaN/Si(111) and GaN flower-like nanostructure
fabricated directly on Si(111) substrate using radio frequency plasma-assisted molecular beam epitaxy. Powder X-ray diffraction
(XRD) and scanning electron microscopy (SEM) were used to study the crystallinity and morphology of the nanostructures. Moreover,
X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) were used to investigate the chemical compositions and optical
properties of nano-flowers, respectively. Activation energy of free exciton transitions in GaN nano-flowers was derived to
be ∼28.5 meV from the temperature dependent PL studies. The formation process of nano-flowers is investigated and a qualitative
mechanism is proposed.