Gd-admixed (Lu,Gd)AlO3 single crystals: breakthrough in heavy perovskite scintillators

• Published in: NPG Asia materials Vol. 13; no. 1
• Main Authors: Pokorný, Martin, Babin, Vladimir, Beitlerová, Alena, Jurek, Karel, Polák, Jan, Houžvička, Jindřich, Pánek, Dalibor, Parkman, Tomáš, Vaněček, Vojtěch, Nikl, Martin
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22-10-2021; Nature Publishing Group
• Subjects: 639/301; 639/301/1005/1009; Aluminum; Atomic properties; Biomaterials; Cerium; Chemistry and Materials Science; Energy Systems; Energy transfer; Gadolinium; Materials Science; Optical and Electronic Materials; Perovskites; Photoluminescence; Scintillation; Scintillation counters; Single crystals; Structural Materials; Surface and Interface Science; Thin Films; Time
• ISSN: 1884-4049; 1884-4057
• DOI: 10.1038/s41427-021-00332-w

We report a breakthrough concept for a bulk single crystal as a heavy aluminum perovskite scintillator, where due to bandgap engineering by a balanced Gd admixture in a Lu cation sublattice, the scintillation performance dramatically increases. In an optimized composition of (Lu, Gd)AlO
3
:Ce (LuGdAP:Ce), the light yield approaches 21,000 phot/MeV, which is close to that of classical but much less dense YAP:Ce and 50% higher than the best LuYAP:Ce reported in the literature. Moreover, contrary to LuYAP:Ce, the LuGdAP host maintains a high effective atomic number close to that of LuAP:Ce (Z
eff
 = 64.9), which is comparable to commercial LSO:Ce. An enormous decrease in afterglow on the millisecond time scale and acceleration in the rise time of the scintillation response further increase the application potential of the LuGdAP host. The related acceleration of the transfer stage in the scintillation mechanism due to diminishing electron trap depths is proven by thermally stimulated luminescence (TSL). Furthermore, we quantitatively characterize and model the energy transfer processes that are responsible for the change in the photoluminescence and scintillation decay kinetics of Ce
3+
in the LuGdAP matrix. Such an innovative (Lu, Gd)AP:Ce scintillator will become competitive for use in applications that require heavy, fast, and high light yield bulk scintillators.
The dependence of the afterglow in millisecond time scale and light yield (in the inset) on the Gd content in the Gd
x
Lu
1-x
AlO
3
single crystal scintillator.