Hydrothermal Preparation Of Transition Metal Doped Zno And Its Optical Properties

As an important II-VI semiconductor, ZnO has a wide band gap of 3.37eV and high exciton banding energy of 60 meV, which is very helpful in the exciton recombination luminescence at room temperature and also in the short wave luminescent devices. Besides, ZnO becomes the hot topic of wide band gap semiconductors for the safety,heat and chemical stability.In this article, zinc acetate and hexamethylene tetramine (HMT) are used as reactants, hydrothermal method is used to prepare intrinsic ZnO powder and Co, Mn doped ZnO materials. The XRD,SEM,EDS,PL test methods are used to describe the crystal structures,composition,surface topography and photoluminescence properties. Also, orthogonal method is used to optimize technological parameter of high quality ZnO powder material. In the base of the optimize technological parameter of intrinsic ZnO, Co,Mn doped ZnO material is synthesized. Also, crystal structures,surface topography and photoluminescence properties are also influenced by doping Co and Mn. What's more, crystal growth and luminous mechanisms are discussed as well. Three parts are included in this article.1,In order to obtain high quality ZnO powder materials, hydrothermal method is used. Also, solution concentration, growing time, temperatures and pH value are used as inspect elements. The optimized technology is that concentration of Zn 0.03mol/L, reaction temperature 140℃, reaction time 10h and the PH value of 9.2,When doped by Co, (002) diffraction peak is shifted to the high-angle direction, the lattice parametrer of doped ZnO becomes smaller, which suggests that doping makes Co into ZnO crystal as displacement. Doping also caused lattice distortion. With the doping rate increasing, the diffraction peak decreased and the surface structures become weaker. The emission peaks are observed at 386nm and 468nm. The purple emission spectra at 386nm are caused by near band exciton radiative recombination. The blue emission spectra at 468nm are caused by the defection of Zni and VZn or Zni and Oi transition.3, When doped by Mn, (002)diffraction peak is shifted to the small-angle direction, The reason is that the solid solubility of Mn is samller than that of Co. Also, the lattice parametrer of doped ZnO becomes lager. When Mn is doped as displacement, the surface structures become uniformed. The emission peaks are observed at 386nm and 468nm. The purple emission spectra at 386nm are caused by near band exciton radiative recombination. The blue emission spectra at 468nm are caused by the defection of Zn; and VZn or Zni and Oi transition.