Eu^(2+)在α-Sr_2P_2O_7中的发光及Eu^(2+)→Mn^(2+)的能量传递

The luminescence of Eu^(2+) in α-Sr_2P_2O_7 and the energy transfer from Eu^(2+) to Mn^(2+)

通过高温固相法制备了一系列不同浓度Eu^(2+)单掺杂和Eu^(2+)、Mn^(2+)共掺杂的荧光材料Sr_(2-x)P2O_7:xEu^(2+)(x=0,0.005,0.01,0.02,0.025)和Sr_(1.99-x)P_2O_7:0.01Eu^(2+),xMn^(2+)(x=0.05,0.1,0.15,0.2).采用XRD、SEM和荧光光谱等手段系统分析了样品的晶相、形貌和荧光性质.分析表明,当焙烧温度为1 050℃时,所得样品属于单相斜方晶系,结晶性良好,颗粒均匀.在355nm紫外光激发下,Sr_2P_2O_7:Eu^(2+)呈现370~480nm的宽带发射,主峰位于418nm,归属于Eu^(2+)的5d-4f允许跃迁,并研究了其浓度猝灭效应及机理.通过共掺杂Mn^(2+)调节荧光色度,实现白光发射.Eu^(2+)作为敏化剂,向Mn^(2+)传递能量,增强Mn^(2+)的d-d跃迁,使其适用于白光发光二极光(WLED)照明.

A series of phosphors Sr2-xP2O7：xEu^2＋（x=0,0.005,0.01,0.02,0.025）and Sr（1.99-x）P2O7：0.01Eu^2＋,xMn^2＋（x=0.05,0.1,0.15,0.2）were synthesized through hightemperature solid-state reaction.The phase,morphology and luminescent properties were characterized by XRD,SEM and photoluminescence analysis.It showed that these samples crystallize in pure orthorhombic with good crystallinity and uniform grains when sintered at 1050 ℃.Under the excitation of 355 nm,a broad emission band ranging from 370～480nm with a peak at 418 nm was obtained in Sr2P2O7：Eu^2＋,which is attributed to the 5d-4fallowed transitions of Eu^2＋.The concentration quenching effect and its mechanism were also discussed.The white emitting can be realized by co-doping with Mn^2＋adjusting the chromaticity.It is suggested that Eu^2＋plays a role of sensitizer and transfers energy to Mn^2＋.The dd transitions of Mn^2＋can be improved by energy feeding from Eu^2＋,which makes it suitable for the application of white light emitting diodes（WLED）.