Synthesis, characterization and growth mechanism of β-Ga 2 O 3 nano- and micrometer particles by catalyzed chemical vapor deposition

Monoclinic β-Ga 2 O 3 nano- and micrometer particles were successfully fabricated on Si(111) substrates with NiCl 2 as a nucleation agent by chemical vapor deposition. Results demonstrated that the sample comprised monoclinic β-Ga 2 O 3 nano- and micrometer particles with diameters ranging from 0.5 to 1.5 μm. FTIR spectra showed well-defined prominent absorption bands at 455 and 694 cm −1 corresponding to Ga–O vibrations. This result is consistent with that of Raman measurements that the typical Ga–O vibration mode was located at 198 cm −1 . Photoluminescence spectrum showed that Ga 2 O 3 nanoparticles had a broad and strong emission band ranging from 300 to 650 nm, which can be attributed to defects such as oxygen vacancies, gallium–oxygen vacancy pairs, and larger surface area of particles. Vapor–solid growth was found to be the mechanism underlying nanoparticle growth, with the nucleation agent Ni 2+ ions playing an important role in the formation of particles because defect energies on the substrate surface were changed.