Similarity between the 0.88-eV photoluminescence in GaN and the electron-capture emission of theOPdonor in GaP

Abstract

A striking similarity has been found between the 0.88-eV photoluminescence (PL) in GaN and the 0.841-eV PL from the substitutional ${\mathrm{O}}_{\mathrm{P}}$ donor in GaP. The major localized phonons, regarded as characteristic for local vibrations involving ${\mathrm{O}}_{\mathrm{P}}$ in GaP, are replicated in the 0.88-eV PL in GaN. This suggests that the 0.88-eV PL can originate from the electronic transition related to the substitutional ${\mathrm{O}}_{\mathrm{N}}$ donor in GaN, either the isolated ${\mathrm{O}}_{\mathrm{N}}$ or a complex involving ${\mathrm{O}}_{\mathrm{N}}.$ Within the first model, the isolated ${\mathrm{O}}_{\mathrm{N}}$ in GaN could be a deep donor and therefore could not be responsible for the residual n-type conductivity.