(Doped Al) ZnO Nanowire Arrays Growth Mechanism And Photoluminescence Properties

Nanowires aligned nanostructures have been attracting much attention in recent years to be fabricated as the field emission display (FED) because of their high efficiency. Compared with CNTs, Zinc oxide emitters are more stable in harsh environment and controllable in electrical properties. The controlling of growth of ZnO nanowires is vital to the applications of ZnO nanowires to the field emission display. So The controlling of growth of ZnO nanowires is the focus research fields. Epitaxial ZnO nanowires array were grown on silicon wafer with Au catalysis by thermal evaporation ZnO powders technique. The ZnO nanowires array is analyzed with X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. This article indicates the changing of face of Si substrates influences the growing mechanism of ZnO nanowires; The growing orientation of ZnO nanowires which grow on Si (100) and Si (111) respectively is not uniform. Which indicates Si substrate can control growing orientation of ZnO nanowires.The energy band of ZnO determines action spectrum of ZnO. Contrarily, the photoluminescence (PL) spectrum reflects the energy band of ZnO. Room-temperature photoluminescence (PL) spectrum of ZnO shows 2 peak at 380nm,480nm in average reports about. Which is explained that the peak of 380nm is near band-edge emission peak and the peak of 480nm is defects luminescence peak averagely. Al-doped ZnO nanowires array were synthesized with Au catalysis on Si(100) substrate using the chemical vapor deposition (CVD) technique. The SEM images show that the ZnO nanowires are perpendicular on the substrate. Room-temperature photoluminescence (PL) spectrum shows 3 near band-edge emission peak at 373nm, 375nm, 389nm. Analysis indicates band gap of Al-doped ZnO nanowaires is 3.343eV and exciton binding energy is 0.156eV. Room-temperature PL spectrum of pure ZnO nanowaires shows 3 near band-edge emission peak at 377nm, 379nm, 389nm. Band gap of pure ZnO nanowaires is 3.301eV and exciton binding energy is 0.113eV. Which shows that the band gap increases because of doping Al.