将ZnS与一定量的氟化物(KF,NH4F)一起煅烧合成出发光性能优良的、具有六方纤锌矿结构的ZnO绿色荧光粉。证明了氟化物的助熔和掺杂双重功能,提出了在较低温度(700℃)下用掺3%KF合成高效绿色荧光粉的基本方法。不同阳离子对ZnO的荧光增强作用与煅烧温度相关。K+对提高带一带吸收效果明显,所以在较低温度下的作用更好,而NH4+对价带一禁带中局域缺陷中心的跃迁贡献较大,在较高温度下仍有很好的增强作用。
Zinc oxide green phosphors with hexagonal wurtzite structure have been synthesized by calcining zinc sulfide and certain amount of fluorides (KF,NH4F). It was proved that the fluorides possess the functions of flux and dopant, which could promote the light-emitting performance of ZnO. A new route for synthesizing the highly effi- cient green phosphors was provided with doping 3% KF at lower calcining temperature (700 ℃ ). The influence of different cations on the fluorescence enhancing of ZnO was related to the calcining temperature. K ~ could increase the effect on the band-to-band absorption, and is beneficial to the preparation of ZnO under lower calcining tempera- ture. While NH4+ has greater contribution to the transition from valence band to defect center in band gap, and shows better enhancing effect for the phosphors calcined at higher temperature.