Luminescence property and magnetic resonance imaging of Gd2O3:Tb3+ nanocrystals doped with Zn2+, Li+

Eroding the Surface of Rare Earth Microcrystals through Vanadate Ions for Considerable Improvement of Luminescence

“…Therefore, doping RE 3+ ions with a low concentration into an appropriate host lattice is widely used to produce solid-solution phosphor and obtain desirable luminescence [2]. In recent years, much attention has been paid to RE 3+doped inorganic materials with a uniform size and specific morphology, because they allow for the attainment of functionalities, not only from the constituent substance but also from the special structure [3][4][5][6]. For rare earth oxide phosphors, calcining the precursors is widely used to obtain the phosphors with a variety of novel structures, since the precursors and their calcined products tend to exhibit generic relationships [3,[7][8][9][10][11].…”

Elucidating the role of metal-ion co-doping towards boosting upconversion luminescence in gadolinium vanadate

“…Various ions such as Li + (ionic radius 92 pm) 15 , Zn 2+ (90 pm) 16 , Na + (118 pm) 17 , and Bi 3+ (117 pm) 18 have been systematically investigated as both alio (oxygen imbalance) and homovalent (charge balanced) dopants. Especially, Li + and Zn 2+ co-doping has attracted considerable attention for a range of inorganic phosphors including fluorides [19][20][21] , binary oxides [22][23][24][25][26] , aluminates 27 , titanates 28,29 , and vanadates 16,[30][31][32][33] . It is reported that with optimized doping concentration, a large (≥10×) improvement in luminescence can be readily obtained.…”

“…Secondly, the presence of Li + /Zn 2+ can act as a flux and lower the calcination temperature in some materials. This can often provide a highly mobile phase for ion-transport leading to formation of larger grains and a reduced number of grain boundaries 26,32 . In larger grains, fewer activator/emitter ions are in close proximity to the defect-rich grain boundaries, thereby reducing non-radiative recombination.…”

“…There is some ambiguity regarding the effects of oxygen vacancies on UC luminescence. The underlying claims range from a role in modification of site-symmetry 36 and acting as sensitizers to improving energy transfer efficiency 16,26 . Finally, other less-common explanations include effects such as reduction in defect density 25 or concentration quenching 35,38 .…”