Effect of in situ Al doping on structure and optical properties of ZnO nanowires grown by MOCVD

Al-doped ZnO nanowires (NWs) were grown on C -axis oriented sapphire by metal organic chemical vapor deposition using dimethylzinc–triethylamine (DMZn–TEN), nitrogen dioxide (NO 2 ) and TMAl as zinc, oxygen and aluminum doping sources respectively. The NWs morphology has been characterized by scanning electron microscopy and transmission electron microscopy. The photoluminescence (PL) spectra exhibit a strong excitonic transition bond that confirms the Al incorporation in the ZnO NWs. Raman results support PL conclusion by showing additional modes in Al-doped ZnO NWs at nearly 270, 510, 579 and 641 cm −1 . The micro-Raman scattering analysis along a single Al-doped ZnO needle-like NW shows an increase of the Al concentration from the basis to the tip of the wire.