Mg_(3)Y_(2)Ge_(3)O_(12)∶Pr^(3+)材料的多色发光及余辉性能

Multicolor Photoluminescence and Persistent Luminescence Characteristics of Mg_(3)Y_(2)Ge_(3)O_(12)∶Pr^(3+) Materials

采用高温固相法制备了一种具有颜色变化的长余辉发光材料Mg_(3)Y_(2)Ge_(3)O_(12)∶Pr^(3+)。通过X射线衍射、激发发射光谱、余辉衰减及热释光曲线等,对样品的结构、发光及余辉性能进行了系统分析。在283 nm激发下,发射光谱在485 nm和609 nm处表现出两个较强的尖峰发射,分别归属于Pr^(3+)离子的^(3)P_(2)→^(3)H_(4)及^(3)P_(0)→3H6能级跃迁。通过对Pr^(3+)离子浓度的调控,有效改变了绿光和红光的相对发射强度,从而实现了发光颜色的多色化。此外,在激发光源停止后该材料同样具有多色的余辉发射,对于最佳样品(Mg_(3)Y_(2)Ge_(3)O_(12)∶0.015Pr^(3+))的余辉时间可达1200 s以上。之后,我们通过热释光曲线具体研究了陷阱的分布及余辉的充放能过程。结果表明,Mg_(3)Y_(2)Ge_(3)O_(12)∶0.015Pr^(3+)材料中浅陷阱的浓度相对较低从而导致室温下的余辉性能较弱。由于材料在高温区域具有超宽带陷阱分布,因此,我们进一步探究了其在高温下的多色长余辉性能。在本工作中,我们成功制备了一种单一离子激活的发光及余辉颜色可调的长余辉发光材料,考虑到其在室温以及高温条件下都具有发光及余辉颜色变化的特点,该材料在高温预警标识以及防伪领域有着潜在的应用价值。

In this paper,a novel Mg_(3)Y_(2)Ge_(3)O_(12)∶Pr^(3+) persistent luminescent material with multicolor luminescence was prepared by high temperature solid phase method.The properties of photo-luminescence(PL)and persistent lu⁃minescence(PersL)were studied by a series of characterization methods such as X-ray diffraction(XRD),PL spec⁃tra,PersL spectra,PersL decay curves and thermoluminescence(TL)curves.The PL spectra exhibit two strong spikes emission at 485 nm and 609 nm under excitation of 283 nm,which can attributed to ^(3)P_(2)→^(3)H_(4) and ^(3)P_(0)→^(3)H_(6) en⁃ergy transitions of Pr^(3+),respectively.By regulating the concentration of Pr^(3+),the relative emission intensity of green and red emission is effectively changed which achieving the multicolor PL.In addition,the material also exhibits multicolor PersL emission after the cessation of the activating light source,and the PersL decay time for the optimal sample(Mg_(3)Y_(2)Ge_(3)O_(12)∶0.015Pr^(3+))can last more than 1200 s.Afterwards,we further investigated the distribution of the trap and the charge,discharge process of the PersL.The results indicate that the concentration of shallow trap in Mg_(3)Y_(2)Ge_(3)O_(12)∶Pr^(3+) is relatively low,which leads to weak PersL performance at room temperature.In addition,be⁃cause the material has an ultra-wideband trap distribution in the high temperature region,we further explored its multi-color PersL performance at high temperatures.In summary,we have successfully prepared a PersL material with single ion activation which can adjust PL and PersL color.Considering its color change characteristics at both room temperature and high temperature conditions,the material has potential application value in the field of high temperature warning signs and anti-counterfeiting.