Characterization of GaNxAs1-x Alloy Grown on GaAs by Molecular Beam Epitaxy

The GaNxAs1-x alloy has been investigated which is grown on GaAs (100) substrate by molecular beam epitaxy with a DC-plasma nitrogen source. The samples are characterized by high resolution X-ray diffraction (HRXRD) and low temperature photoluminescence (PL) measurements. Both HRXRD and PL measurements demonstrate that the crystalline and optical qualities of GaNxAs1-x alloy degrade rapidly with the increase of N composition. The nitrogen composition of 4.5 % can be obtained in GaNxAs1-x/GaAs quantum well by optimizing growth conditions,through which a photoluminescence peak of 1201nm is observed at a low temperature (10 K). The dependence of GaNxAs1-x band gap energy on the nitrogen composition in this investigation corresponds very well with that of the theoretical one based on the dielectric model when considering the effect of the strain. At the same time,we also demonstrate that the bowing parameter of GaNxAs1-x alloy is composition dependent.