摘要
为提高磷酸钠钙红色荧光粉的发光强度,采用高温固相法制备了Na_(1.3)Ca_(0.4-x)Sr_xPO_4:0.3Eu^(3+)系列荧光粉,通过X-射线衍射仪(XRD)和荧光分光光度计分析该系列样品的物相结构、发光性能以及最佳掺杂浓度。XRD结果表明,Sr^(2+)取代Ca^(2+)占据中心格位,晶相有逐渐由NaCaPO_4向NaSrPO_4转变的趋势,结晶性能良好。荧光光谱分析表明,随着Sr^(2+)掺杂浓度的提高,在近紫外光区的395 nm和蓝色光区的465 nm处的激发峰强度均显著增强。由于掺杂离子之间电负性和离子半径的差异,导致电子云效应的形成和晶体场强度的降低,增大了~5D_0→~7F_2跃迁发射的能量,使得在618 nm处的发射峰强度明显提高,而且其峰位逐渐向短波长方向移动。当Sr^(2+)完全取代Ca^(2+)后,荧光粉发射强度提高了21%,表明Na_(1.3)Ca_(0.4-x)Sr_xPO_4:0.3Eu^(3+)是一种有望应用于白光发光二极管的红色荧光粉。
A series of Na1.3Ca0.4-xSrxPO4:0.3Eu3+ phosphors were prepared by high temperature solid state reaction. The phase structures and luminescent properties of the materials were analyzed by X-ray diffraction(XRD)and fluorescence spectroscopy respectively,which then helpfully determined the optimum dopingconcentrations of the samples. XRD results show that Sr2+replaces Ca2+and occupies the central lattice,andthe crystalline phase of NaCaPO4 almost changes into that of NaSrPO4 with the fine crystallinity. Thefluorescence spectroscopy shows that the excitation intensities of the peak at 393 nm in near ultraviolet regionand the one at 465 nm in blue light region enhances with increasing doping concentration of Sr2+. Thedifferences of electronegativity and ionic radius between the dopes ions result in the formation of electron cloudeffect and the reduction of crystal field intensity,which enhances the transition of 5D0→7F2. Herein,the relativeintensity of emission peak at 618 nm increases with increasing concentration of Sr2+and the peak positiongradually moves towards shorter wavelength. In addition,the emission intensity increases by 21% when Sr2+completely replaces Ca2+,indicating that Na1.3Ca0.4-xSrxPO4:0.3Eu3+ is expected to be a new red phosphor used in white light-emitting diode.
作者
孔仕进
张占辉
彭伟康
齐同刚
黄志良
KONG Shijin;ZHANG Zhanhui;PENG Weikang;QI Tonggang;HUANG Zhiliang(School of Materials and Engineering,Wuhan Institute of Technology,Wuhan 430205,China)
出处
《武汉工程大学学报》
CAS
2018年第6期637-640,共4页
Journal of Wuhan Institute of Technology
基金
国家自然科学基金(51374155)
湖北省自然科学基金(2014CFB796)
湖北省科技支撑计划项目(2015BAA105
2014BCB034)
