Comparison between dilute nitrides grown on {111} and [100] GaAs substrates: N incorporation and quantum well optical properties

Molecular beam epitaxy of GaAsN/GaAs and GaInAsN/GaAs structures on {111} oriented substrates has been studied. Ga(In)AsN/GaAs thick layers and quantum wells have been grown on [111]A and [111]B GaAs substrates. Nitrogen incorporation has been found to depend on substrate orientation and growth rate. The most promising orientation appears to be the [111]A orientation for GaAsN quantum wells and emission wavelengths up to 1.5 (mu)m have been obtained. For [111]B, a broad emission is systematically observed indicating the presence of defects originating from N incorporation. For [111]A GaInAsN/GaAs quantum wells, the addition of indium leads to a red shift and to a broadening of the emission. It does not have any beneficial effect on [111]B quantum well optical properties.