Optical Properties of Nanocrystalline GaN Films Prepared by Annealing Amorphous GaN in Ammonia

Abstract

Nanocrystalline GaN films were prepared by thermal treatment of amorphous GaN films under flowing NH 3 at a temperature of 600°C to 950°C for 1 h to 2 h. X-ray diffraction and field-emission scanning electron microscopy confirmed the formation of high-crystal-quality hexagonal GaN films with preferential (002) orientation. The photoluminescence spectrum showed a sharp peak near the band gap emission located at 368 nm and a broad blue peak centered at 430 nm. Five first-order Raman modes near $143 cm -1 , 535 cm -1 , 555 cm -1 , 568 cm -1 , and 731 cm -1 with two new additional Raman peaks at 257 cm -1 and 423 cm -1 were observed. The origin of these new Raman peaks is discussed briefly.

Optical properties of Si-doped GaN nanocrystals in SiO2/GaN/SiO2thin film structure

“…The sharp peak located at 368 nm may correspond to the near-band-gap emission which is very close to the band gap of bulk GaN (E g = 3.4 eV, 365 nm). This observation is in conformity with that reported by Zhang et al [28] for nanocrystalline GaN films. There was no noticeable shift in the peak position for the films deposited at different substrate temperatures during deposition.…”

Structural and optical properties of GaN:Eu nanoparticles synthesized by simple ammonification method

“…In our previous research [24], similar broadening behaviors of the doped GaN nanostructures have been analyzed in details. Then, based on our previous research results, two extra Raman peaks at 255 and 419 cm −1 in this case can be attributed to the confinement by the C 4 6v space group in first-order Raman scattering.…”

Optical Properties of Semiconductor Nanomaterials

“…GaN nanostructures, including nanoparticles, thin films, quantum wells, nanowires and nanorods, have received considerable attention as a potential blue emitting laser or LED material [65][66][67][68][69][70][71][72][73][74][75][76]. Bulk GaN is direct bandgap semiconductor with a bandgap energy of 3.4 eV at room temperature.…”