Deposition of Amorphous GaN by Compound Source Molecular Beam Epitaxy for Electroluminescent Devices

Abstract

Amorphous GaN films were deposited using compound source MBE. GaN powder was used as the source material and no additional nitrogen sources were supplied. Although the N/Ga ratio in the layers deposited at temperatures lower than 400 °C was low, an increase of the substrate temperature improved the N/Ga ratio. The emission peaks of their photoluminescence spectra originated around the band edge of hexagonal GaN. Electroluminescent devices based on amorphous GaN were fabricated and were found to show UV emission. Amorphous GaN is one of the candidate materials for light‐emitting devices operating in the UV to the blue spectral regions.

Amorphous GaN‐Based Electroluminescent Devices Operating in UV Spectral Region

“…Because it contained hydrogen, the source was annealed in vacuum at 900 C for more than ten hours. The GaN powder was yellow before annealing, but became white after annealing [5]. Ammonia was supplied during film deposition, at a flow rate of less than 0.1 sccm.…”

Gallium nitride thin films as processed by several techniques: Their possible applications for PV-devices

“…This band originates from the trap states that can be generated from intrinsic defects due to N vacancies which are not so prevalent in the stoichiometric composition. This value agreed with the optical band gap of a-GaN calculated from ab initio molecular dynamics [9] and the blue luminescence shown in the a-GaN deposited by compound source molecular beam epitaxy.…”

Low-temperature growth of GaN layers on (0001)6H–SiC by compound source molecular beam epitaxy

“…Although the surface cracks or residual strain is partly due to the lattice mismatch between nitride epilayers and the substrate, the difference in thermal coefficient leads to the formation of surface cracks or residual strain in the epitaxial layer. 7 These results indicate that the CS-MBE technique will be effective in the realization of the GaN epitaxial growth at low growth temperatures. The growth temperature of GaN by metalorganic vapor phase epitaxy ͑MOVPE͒ is required to be approximately 1000°C for the fabrication of light-emitting devices.…”