High-throughput production of LuAG-based highly luminescent thick film scintillators for radiation detection and imaging

Abstract

Radiography is non-destructive imaging for engineering, medical diagnostics, airport security checks, and decontamination activities in nuclear plants. Inorganic scintillators are phosphor materials that convert radiation into visible photons with high luminescence and fast response, and scintillators with a few tens of micrometers thickness can improve sensitivity in radiation detection and imaging. To date, a production method for thick film scintillators is a time and cost consuming way of slicing and poshing bulk single crystals and transparent ceramics. Here, the chemically vapor deposited Ce3+-doped Lu3Al5O12 thick film scintillators (CVD-Ce3+:LuAG) with a thickness of 1–25 μm were produced at deposition time of 1–30 min. Numerical simulations indicated the penetration depth of α-particle in Ce3+:LuAG is 12.8 μm, and the 14-μm-thick CVD-Ce3+:LuAG showed highest light yield (31,000 photons 5.5 MeV−1), superior to the commercial Ce3+:LuAG single crystal scintillator (21,000 photons 5.5 MeV−1). In the X-ray radiograph taken with CVD-Ce3+:LuAG as a scintillation screen, 5-μm-width bar of metal microgrids can be identified. Vapor deposition technique can be a novel high-throughput production way of a thick film scintillator which is in a micrometer-thickness effective to converting radiations into photons for sensitive α-emitter detection and high-resolution X-ray imaging.

Scintillation properties of transparent Lu‐α‐SiAlON:Ce3+ ceramics

“…The light yield of the developed transparent Lu‐α‐SiAlON ceramics was calculated as 1300 photons 5.5 MeV −1 . This value is lower than those reported for transparent or translucent α‐ray‐scintillator such as ZnO ceramics 39 (prepared by spark plasma sintering, 44200 photons 5.5 MeV −1 ), ZnO:Cd film 8 (by liquid phase epitaxy method, 18000 photons 5.5 MeV −1 ), Lu 3 Al 5 O 12 (LuAG) film 30 (by CVD, 31000 photons 5.5 MeV −1 ), and LuAG single crystal 30 (21000 photons 5.5 MeV −1 ). A phenomenological model is usually used to explain the observed light yield, 1,6,40 which is formulated as: $$$$\begin{equation}LY\ = \frac{E}{{{{E}_{\mathrm{g}}}\beta }}\ \times S \times Q\end{equation}$$$$where, $$LY$$ is the scintillation light yield, $$E$$ is the deposited energy of ionizing radiation, $$\beta $$ is the constant parameter, $${{E}_{\mathrm{g}}}$$ is the band‐gap energy, $$S$$ is the energy migration efficiency from the host to emission centers, and $$Q$$ is the quantum efficiency which is equal to the photoluminescence quantum efficiency.…”

“…The light yield of the developed transparent Lu-α-SiAlON ceramics was calculated as 1300 photons 5.5 MeV −1 . This value is lower than those reported for transparent or translucent α-ray-scintillator such as ZnO ceramics 39 (prepared by spark plasma sintering, 44200 photons 5.5 MeV −1 ), ZnO:Cd film 8 (by liquid phase epitaxy method, 18000 photons 5.5 MeV −1 ), Lu 3 Al 5 O 12 (LuAG) film 30 (by CVD, 31000 photons 5.5 MeV −1 ), and LuAG single crystal 30 (21000 photons 5.5 MeV −1 ). A phenomenological model is usually used to explain the observed light yield, 1,6,40 which is formulated as:…”

“…The measurement procedures of the scintillation properties were previously reported 30 . 241 Am source was used as a 5.5‐MeV α‐ray source.…”

Chemically vapor deposited oxide-based thick film scintillators

“…34) X-ray imaging test using CVD-Ce 3+ :LuAG thick film scintillator as a scintillation screen will be reported elsewhere. 35)…”

Novel Detector Configurations in Cone-Beam CT Systems: A Simulation Study

“…Moreover, although LaBr 3 :Ce is hygroscopic, it receives great scientific attention because of its rapid response to incident photons (~20 ns [22]). Likewise, CZT is a material that is under investigation as an adequate X-ray CT system detector since it presents decreased electronic noise (a magnitude of nA [23]) and an increased signal-to-noise ratio [11,[24][25][26].…”