Photoluminescence study of the GaAs barrier effect on GaAs/GaInAs/GaAs quantum wells

In this work we propose a photoluminescence (PL) study of a GaAs/GalnAs/GaAs quantum well (QW) sandwiched between two GaAs_0.95N_0.05 layers grown on GaAs substrate by molecular beam epitaxy (MBE). This structure is used as an optical switch in the telecommunication application. The effect of the GaAs barrier thickness (d) between the GaAs/GalnAs/GaAs QW and GaAsN plan was investigated for three samples with d = 25, 40 and 100 Adeg. We have found that at low temperature the PL spectra are essentially composed of a wide band and two sharp structures. We have attributed the wide band to the deep localized state due to the three-dimensional mode growth of the GaAsN layer at low temperature, and the two sharp structures to the fundamental states of GalnAs QW and GaAsN layers. The dependence of the energy shift with the GaAs barrier width of the two structures is explained in the frame of the coupling of the two states by the covering of their wave functions.