Optical and Scintillation Properties of Tb-Doped Rare-Earth Pyrosilicate Single Crystals

Series of 1.0% Terbium (Tb)-doped rare-earth pyrosilicate single crystals including Lu₂Si₂O₇ (LPS), Y₂Si₂O₇ (YPS), Gd₂Si₂O₇ (GPS), and La₂Si₂O₇ (LaPS) have been prepared by the floating-zone method. After the phase confirmation by powder X-ray diffraction, the properties are measured on both photoluminescence and scintillation aspects, including the photoluminescence emission contour graph and decay times, X-ray induced scintillation spectra and decay times, afterglow profiles, and the recently developed pulse height spectra for scintillators with millisecond decay time. The results indicate the multiple emissions from Tb³⁺ 4f-4f transition with the dominant emission at 540 nm (⁵D₄ → ⁷F₅) on both ultraviolet and X-ray excitation with the decay time around 2.6–5.6 and 1.3–3.2 ms, respectively. Under the γ-ray irradiation from ¹³⁷Cs, the Tb-doped LPS, YPS, GPS, and LaPS have presented scintillation light yields of 20,700, 29,600, 95,600, and 47,700 ph/MeV with ±10%, respectively, which considerably very high among the oxide scintillators.