Temperature effect on silicon n-doped GaAs1-x Nx layers studied by photoluminescence

Actually, III-V-N alloys are receiving a considerable attention due to the extend wavelength range that can be covered by devices based on these materials. It was found that the incorporation of a small amount of notrogen ( X < 5% ) red shifts the bandgap and affects considerably the electronic and optical properties of the III-V matrix. In this work, we present the effect of the silicon n-doping on GaAsN0.015 layers using photoluminescence measurements (PL). The study is carried out on a set of three GaAsN0.015 samples grown by Molecular Beam Epitaxy (MBE) on GaAs (001) oriented substrate using a radio frequency (rf) N radical beam source. In order to determine the nature of these structures PL meseaurements in the range of 10 to 190K were performed; we note that the structure at 1.20 eV disappears at high temperature, but the line at 1.25eV persists, this behaviour characterise respectively nitrogen localized stete and GaAsN0.015 bandgap, we note that the intensity of the wide band decreases when the silicon content increases, this effect is interpreted by the saturation of nitrogen localised states by the silicon atoms