The three AlGaAs/GaAs multi-quantum well (MQW) structures which have different Al compositions rate were grown on undoped semi-insulating GaAs(100) substrate by solid source molecular beam epitaxy(MBE) with continuous growth (CG) method at 580 oC. The MQW (QWIP) structures consists of 50 periods of n-GaAs wells and AlGaAs barriers sandwiched by n-GaAs top and bottom contact layers. Reflection high-energy electron diffraction oscillations were observed during molecular beam epitaxy. The microstructures of the MQWs were characterized by high resolation X-ray measurement and the low temperature photoluminescence (PL) properties of the MQWs were also studied. The layer thickness and the barrier composition were determined from the PL peak energy and the x-ray rocking curve simulation. In addition, the optical gaps and the Al concentration of the structure were also estimated by direct interpretation of the pseudo-dielectric function spectrum using spectroscopic ellipsometry (SE).
Acknowledgments: This work was supported by the Turkish Prime Ministry State Planning Agency under projects No. 2001K120590