Eu3+ red long afterglow in Y2O2S:Ti, Eu phosphor through afterglow energy transfer

Persistent luminescence in rare earth ion-doped gadolinium oxysulfide phosphors

“…(2) The emission band could be caused by the recombination of electron and hole on Ti 4+ , which is similar to the charge balance requirement due to the nonequivalent substitution of Gd 3+ by the changeable valence Ti ions [19,27]. This process may occur in two steps: initially, Ti 4+ captures one electron under UV light to form the excited Ti 3+ * ion (Ti 4+ + e → Ti 3+ *), which has a hole affinity, may then capture a hole which results in emission, Ti 3+ * + hole → Ti 4+ + h. It should be noted that the essential mechanism of the afterglow emission of Ln 2 O 2 S:Ti (Ln = Y, Gd) is still unclear because of the lack of specific data, as discussed later, however, it is certain that the emission band located at 590 nm plays an important role in the LLP of the rare earth ion-doped Ln 2 O 2 S phosphors [17,18,20,22,23,26].…”

“…There are three possible types of trapping state in rare earth iondoped oxysulfide [18][19][20]24,26,41]: (1) isoelectronic traps formed by ions which have a high electron (or hole) affinity, (2) charge traps formed by nonequivalent replacement of ions and (3) anion vacancies (sulfur or oxygen). When typical activators such as Eu 3+ and Tb 3+ were introduced into oxysulfide hosts, isoelectronic traps created by the replacement of Ln 3+ constituent is regarded [44].…”

“…This important founding has initiated 0925-8388/$ -see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2010.01.141 a lot of interesting in the LLP of this phosphor and its analogues [18][19][20][21][22][23][24][25][26][27][28][29][30]. It was reported that co-doping with Mg and especially Ti ions affected the phosphorescence of Y 2 O 2 S:Eu 3+ phosphor, and the Ti component can be substituted by Zr or Ta [17].…”

Improving pure red upconversion emission of Co-doped Y2O3:Yb3+–Er3+ nanocrystals with a combination of sodium sulfide and surfactant Pluronic-F127

“…Both Y 2 O 3 :Eu 3+ and Y 2 O 2 S:Eu 3+ are commercially available and present an external quantum efficiency higher than 45% in the red region [39,40]. The synthesis of monodisperse nanospheric, red-emitting phosphors such as Y 2 O 2 S:Eu 3+ has been previously accomplished by a precipitation technique followed by a sulfur treatment process in a CS 2 atmosphere.…”

Long lasting phosphorescence of Gd2O2S:Eu,Ti,Mg nanorods via a hydrothermal routine

“…This excited news sparked people's interest in finding long persistent red phosphorescent phosphor within the oxysulfide system. In recent years, the works on red persistent phosphors have been focused on the Eu 3+ activated rare earth oxysulfides, such as Y 2 O 2 S:Eu and La 2 O 2 S:Eu [9][10][11][12][13]. Generally, such oxysulfides are obtained by solid phase reaction, which enables the manufacturers with mass production.…”