Cl~-,S~(2-)共掺杂氧化锌荧光粉的制备及发光性能

在空气气氛中,以NH_4Cl为助剂,通过热氧化硫化锌,制备出Cl~-,S~(2-)共掺杂氧化锌荧光粉,激发和发射光谱随氧化温度的变化而变化.在350nm激发下,氧化锌荧光粉的发射光谱只有510nm绿色峰,并有黄色区拖尾现象.绿色峰强度随煅烧温度的变化而变化.绿色峰归因与一价氧空位中的电子和价带中光生空穴的复合.氧化锌荧光粉的光致发光谱的变化是Cl~-,S~(2-)共掺杂的结果.

Preparation and photoluminescence properties of chloride and sulfur co-doped zinc oxide phosphor

Chloride and sulfur co-doped ZnO green phosphor, was prepared by thermal oxidation of zinc sulfide un-der the assistant of ammonium chloride in air atmosphere. The excitation and emission spectra were observed to vary signif-icantly with oxidation temperature. The photohiminescence spectra of the ZnO phosphors under excitation wavelength at 350 nm showed only one green emission peak at around 510 nm presenting a tail in the yellow region. According m accept-er-donor transition mechanisms, this green emission band can be ascribed to a transition of a photogenerated electron from the localized defect centers (donor) to a deeply trapped hole (acceptor) in the bandgap. It was suggested that the trapping rate of hole or electron must be much faster than the radiative recombination rate of the exciton emission, which results in the strong green emission. The study on the PL spectra of the ZnO phosphors revealed that the green luminescence intensi-ty depended on both Zn~+ sites and Vo~+ , which were formed on the calcinations process and influenced greatly by the co-do-ping of Cl,S.