MOVPE growth and optical characterization of GaAsN films with higher nitrogen concentrations

Abstract

AbstractWe have successfully grown high‐N‐content GaAsN films up to 5.1% on GaAs(001) substrates using tertiarybutylarsine (TBAs) as the As precursor by metalorganic vapour phase epitaxy (MOVPE). The narrow X‐ray diffraction (XRD) peaks and clear Pendellosung fringes indicate that the GaAsN/GaAs interface is fairly flat and the GaAsN layers are uniform. By the photoluminescence (PL) measurement at 10 K, the clear PL peaks related to the near‐band‐edge transition could be detected and the bandgap energy was red‐shifted to 1.16 eV in 1.9%‐N GaAsN film. But, in higher N‐content films no peak could be detected. So, post growth annealing in the reactor was applied to 4.7% and 5.1%‐N films, and resulted in an enhancement of the PL peak intensity, and the bandgap energy of 5.1%‐N film was consequently determined to be 0.95 eV at room temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)