UV-白光 LED用硫化鋅系列奈米螢光粉體之合成及其特性探討

Abstract Zinc sulfide (ZnS), as II-VI semiconductors with a wide band gap energy of 3.68eV, have received much attention due to their excellent luminescence properties and are commercially used in electroluminescence devices. They are candidate materials for phosphors that emit visible light. The major and important applications of phosphors are used as light sources, display devices, radiation detectors and so on. In this study, we prepare the nano-scaled ZnS based phosphors using solid state method and chemical precipitation method. Different dopants (Mn, Cu, Mg, Eu) have been introduced in the system. X-ray diffraction pattern, SEM, TEM, PL and CIE measurements have been used to investigate the characteristics of ZnS-based nano-phosphors for UV-white light LED applications. Firstly , we synthesize and characterize the luminescence properties of ZnS：Mn nanophosphors by solid state method with different S/Zn ratio and under different temperature. When S/Zn ratio is 0.65 and under 300℃, a near white light phosphors are obtained and C.I.E. is (0.309,0.311). Secondly, ZnS:Mn+2,ZnS:Cu+2 and ZnS:Eu+3 phosphors are prepared by chemical-precipitation method. From the emission spectra data, orange light with the emission peak at 593nm for ZnS:Mn+2 phosphors are detected, blue light at 470nm and green light at 520nm for ZnS:Cu+2 phosphors are detected, red light for ZnS:Eu+3 phosphors are also detected. It is possible to obtain white light phosphors by co-doping Cu+2,Eu+3 and Cu+2,Mn+2 in this system Thirdly, ZnS co-doped Mg+2 and Mn+2 phosphors are synthesized by chemical precipitation method. From the emission spectra data, near white light is observed for Zn0.49Mg0.49S: Mn+2 (2mol%) and C.I.E is(0.322,0.292).