Dependence of scintillation properties on cerium concentration for GPS single crystal scintillators grown by a TSSG method

Single crystal Gd
₂
Si
₂
O
₇
:Ce (GPS:Ce) scintillators were grown by a top seeded solution growth (TSSG) method and their crystal structures and scintillation properties were measured. Single crystal GPS with several cerium concentration; (Gd
_1-x
Ce
_x
)
₂
Si
₂
O
₇
(x=0.025, 0.1, 0.15), were synthesized with a RF-Czochralski furnace. For GPS:Ce 2.5 at.%, a crystal structure was orthorhombic. For GPS:Ce 10 and 15 at.%, these were triclinic. In PL measurements, broad emissions around 350 to 450 nm correspond to 5d-4f transitions of Ce
³⁺
were observed. In gamma-ray measurements, each scintillator shows light output larger than that of BGO. High energy resolution of around 5% was obtained for GPS:Ce 2.5 and 10 at.%. GPS:Ce 2.5 at.% shows ca. 4.4 times light output larger than that of BGO. Decay times of triclinic GPS were faster than that of orthorhombic GPS.