Fundamental study of growth of (ZN,CD)SE on GAAS(211)B from hetero-interface to nanostructures

This thesis presents the results and conclusions drawn from a systematic study of the growth of ZnSe, ZnCdSe single and multiple layers, and CdSe overlayers grown by molecular beam epitaxy (MBE) on GaAs (211)B substrates. Using reflection high-energy electron diffraction (RHEED), two GaAs surface reconstructions are identified related to incomplete and complete removal of the GaAs oxide. From atomic layer epitaxy (ALE) and MBE growth experiments, the zinc and selenium stabilised surface reconstructions are identified for ZnSe and ZnCdSe (211)B samples. The surface reconstructions observed are dependent on growth temperature, the Se/Zn flux ratio and the GaAs substrate surface reconstruction. It is also established that the growth mode of (Zn,Cd)Se layers is step flow. Photoluminescence spectroscopy (PL) is used to assess the quality of ZnSe and ZnCdSe epilayers. High quality ZnSe and ZnCdSe (211)B epilayers are achieved by optimising the growth conditions with respect to the PL spectrum. Preliminary studies on CdSe overlayers on ZnSe (211)B layers characterised by RHEED and atomic force microscopy (AFM) are also presented. The cadmium and selenium stabilised (211)B surface reconstructions are identified from ALE growth experiments and their dependence on growth temperature established. Results from AFM show that CdSe nanostructures on ZnSe (211) are elongated along the [1-bar11] azimuth. (author)Available from British Library Document Supply Centre-DSC:DXN042566 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo