Structural and optical properties of MBE grown GaNAs/GaAs quantum well structures

Structural and optical properties of GaNAs/GaAs quantum well (QW) structures are studied by performing X-ray diffraction (XRD) and photoluminescence (PL) measurements. Arsenic-rich GaNAs layers were grown by molecular beam epitaxy with a water-cooled nitrogen plasma cell. The nitrogen content x of our GaNxAs1−x layers were in the range of 0.5–2%. Clear PL signals with a tail in the low energy side were observed from GaNxAs1−x/GaAs QWs. The positions of these PL peaks are roughly explained by theory using a reported bowing parameter. Electrical properties of a selectively doped GaAs/GaNxAs1−x/n-AlGaAs structure were also studied. It is found that electrons are accumulated in the GaNAs layer . The fluctuation of alloy compositions appears to have a dominant effect on electron mobilities.