Enhanced Red Phosphorescence in MgGeO[sub 3]:Mn[sup 2+] by Addition of Yb[sup 3+] Ions

Abstract

Enhancement of the 4 T 1g ͑ 4 G͒ → 6 A 1g ͑ 6 S͒ red emission of MgGeO 3 :1% Mn 2+ with addition of Yb 2 O 3 is reported. The initial phosphorescence in the Yb 2 O 3 codoped sample is an order of magnitude stronger than that of the Yb 2 O 3-free sample. Thermoluminescence spectra indicate that the introduction of Yb 3+ into the host produces traps with a suitable depth, resulting in the enhanced red phosphorescence of Mn 2+. The possible mechanism for this phenomenon is explained by a competitive trapping model.

How to induce highly efficient long-lasting phosphorescence in a lamp with a commercial phosphor: a facile method and fundamental mechanisms

“…On the contrary, codoping of cations with larger ionization potentials correspondingly results in higher numbers and deeper depth of the deep traps (578 K). The same was observed in almost all of the other examples.Table 3shows a summary of the ionization potentials of ions and the influences of co-dopants on the TL peaks previously reported for some phosphors 23,24,32,[54][55][56][57][58][59][60][61][62][63][64][65]. It is obvious that when the ionization potentials of co-dopants such as Yb 3+ cations are lower than that of Mn2+ , the intensity of the TL peak at low temperature is increased and is shifted to a lower temperature.…”

“…Table 3 shows a summary of the ionization potentials of ions and the influences of co-dopants on the TL peaks previously reported for some phosphors. 23,24,32,[54][55][56][57][58][59][60][61][62][63][64][65] It is obvious that when the ionization potentials of co-dopants such as Yb 2+ , Eu 2+ , Sm 2+ , Tm 2+ and Zr 3+ cations are lower than that of Mn 2+ , the intensity of the TL peak at low temperature is increased and is shifted to a lower temperature. Oppositely, the co-dopants with larger ionization potentials such as Ca 2+ , Sr 2+ , Ba 2+ , and other Ln 3+ cations would increase the density and depth of deep traps corresponding to the TL bands in a higher temperature region.…”

Red and near infrared persistent luminescence nano-probes for bioimaging and targeting applications

“…Several other phosphors in different hosts, e.g. silicates, [81][82][83][84][85][86][87][88][89][90] germanates, 91,92 nitrides, 93 stannates, 94 phosphates, [95][96][97][98][99][100][101][102] aluminates, 103 titannates, 104,105 metal oxides, 106,107 uorides, 108 and others, 109 have also been developed for getting long aerglow emission in the red region. Table 1 gives a comprehensive detail of the host, dopant ions, colour/wavelength of the aerglow emission, persistent time, and remarks, if any of red emitting persistent phosphors.…”

Tunable trap depth in Zn(Ga1−xAlx)2O4:Cr,Bi red persistent phosphors: considerations of high-temperature persistent luminescence and photostimulated persistent luminescence

“…Until now, considerable research efforts have been devoted to (i) synthesizing new red or NIR persistent phosphors, generally in bulk at rst; [7][8][9][10] (ii) optimizing the persistent properties, by codoping, for example; [11][12][13][14][15] and (iii) exploring approaches to obtain nano-sized particles. 2,3,7 However, little attention has been given to the effect of temperature on the persistent performance.…”