Use of codoping to modify the scintillation properties of inorganic scintillators doped with trivalent activators
Crystals with improved scintillation and optical properties are achieved by codoping with a trivalent dopant and a divalent and/or a monovalent dopant. Embodiments include codoping LSO, YSO, GSO crystals and LYSO, LGSO, and LYGSO crystals. Embodiments also include codoped crystals with a controlled monovalent or divalent:trivalent dopant ratio of from about 1:1 for increased light yield to about 4:1 for faster decay time.
1. A scintillation material, comprising a crystal consisting essentially of:
T 2x Lu 2(1-x-y-z) Y 2y Gd 2z SiO 5 ; and
at least one divalent codopant,
wherein T is a trivalent activator dopant selected from the group consisting of Pr, Eu, Er and Yb,
0<2x<0.2,
0≦2y≦2(1−x),
0≦2z≦2(1−x), and
0≦(y+z)≦(1−x),
wherein the ratio (a):(b) of the divalent dopant concentration (a) to the trivalent activator dopant concentration (b) is about 1:1, to maximize light output.
2. The scintillation material according to claim 1 , wherein 0≦(y+z)<(1−x), such that the crystal includes Lu.
3. The scintillation material according to claim 1 , wherein the divalent codopant comprises Mg, Ca, Ba, Zn, or Cu.
4. The scintillation material according to claim 3 , wherein the trivalent activator dopant consists of Pr and the codopant comprises Ca.
5. A medical imaging device comprising the scintillation material according to claim 1 .
6. A positron emission tomography (PET) scanner comprising the scintillation material according to claim 1 .
7. A laser device comprising the scintillation material according to claim 1 .
8. An oil exploration device comprising the scintillation material according to claim 1 .
9. An optical data storage device comprising the scintillation material according to claim 1 .
10. A scintillation detector comprising the scintillation material according to claim 1 .
11. A method comprising detecting gamma rays, X-rays, cosmic rays, and particles having an energy of 1 keV or greater using the scintillation detector according to claim 10 .
12. A scintillator material comprising a ceramic comprising:
T 2x Lu 2(1-x-y-z) Y 2y Gd 2z SiO 5 ; and
at least one monovalent and/or divalent codopant,
wherein T comprises at least one trivalent activator dopant,
0<2x<0.2,
0≦2y≦2(1−x),
0≦2z≦2(1−x), and
0≦(y+z)≦≦(1−x).
13. A method comprising growing a crystal consisting essentially of:
T 2x Lu 2(1-x-y-z) Y 2y Gd 2z SiO 5 ; and
at least one monovalent and/or divalent codopant,
wherein T is a trivalent dopant selected from the group consisting of Pr, Eu, Er and Yb,
0<2x<0.2,
0≦2y≦2(1−x),
0≦2z≦2(1−x), and
0≦(y+z)≦(1−x),
the method further comprising controlling the ratio (a):(b) of the divalent dopant concentration (a) to the trivalent activator dopant concentration (b) to about 1:1 when the codopant is divalent.
14. A scintillation material, comprising a crystal consisting essentially:
T 2x Lu 2(1-x-y-z) Y 2y Gd 2z SiO 5 ; and
at least one divalent codopant,
wherein T is a trivalent activator dopant selected from the group consisting of Pr, Eu, Er and Yb,
0<2x<0.2, and
0<2(y+z)≦2(1−x),
wherein the ratio (a):(b) of the divalent dopant concentration (a) to the trivalent activator dopant concentration (b) is about 1:1, to maximize light output.
15. The scintillation material of claim 14 , wherein x+y+z is substantially 1.