Luminescence from the deep level N–N interstitials in GaAsN grown by metal organic chemical vapour deposition

Abstract

Strong luminescence from the nitrogen–nitrogen (N–N) interstitials had been observed in GaAsN epilayers grown by metal organic chemical vapour deposition (MOCVD) using nitrogen as the carrier gas. These N–N interstitials in the GaAsN films were thoroughly studied through photoluminescence (PL) and secondary ion mass spectroscopy (SIMS) measurement combined with X-ray diffraction (XRD) measurement. The N–N interstitial emission peak resided at deep level of 0.2–0.23 eV below the inter-band gap transition energy of the GaAsN epilayer. The N–N interstitial PL intensity decreased after the GaAsN samples were thermal annealed. It had also been found that the N–N interstitials contribute to the substitutional nitrogen composition of the GaAsN epilayer after rapid thermal annealing were carried out on the GaAsN epilayer.