Enhanced green fluorescence and afterglow in (Zn, Mg)2GeO4: Mn2+, Cd2+

• 来源期刊: 中国科学:物理学 力学 天文学（英文版）
• 年，卷（期）: 2017,（9）
• 页码范围: 76-79
• 页数: 4页
• 语种: 英文
• DOI: 10.1007/s11433-017-9055-y

摘要

Long-lasting phosphorescent (LLP) materials have attracted considerable attention since green and blue emitting persistent Eu2+ doped alkaline earth phosphors were reported in the mid-1990s [1-3].Over the past few decades,a considerable effort has been made to design novel LLP materials for a wide range of applications such as emergency lighting,interior decoration,road signs,and in vivo bioimaging [4-6].For these applications,long persistence times are often desirable.Two types of active center involved are:emitters and traps in LLP phosphors.Emitters are capable of emitting radiation after being excited,and their color is determined by the emission wavelength of the LLP phosphor.Traps states usually do not emit radiation,but store the excitation energy later releasing it to the emitters under thermal disturbance.Thus,traps play an important role in photo-energy storage of LLP phosphors.The trap type and trap distribution are generally associated with lattice defects and/or co-dopants.The overall nature of the trap states determines the persistence intensity and time.Thus,design of LLP phosphors focuses on generating suitable trap levels and trap densities.