Composition Tailoring in Ce-Doped Multicomponent Garnet Epitaxial Film Scintillators

Bulk single crystals of multicomponent garnet scintillators Lu3–xGdxGayAl5–yO12:Ce exhibit much improved scintillation properties in optimized composition islands (x = 2–3, y = 2–3) compared to the simple Lu3Al5O12:Ce one. Namely, a much higher light yield, less intense slow component in the scintillation response, and better energy resolution have been achieved. This work shows that comparable enhancement of the scintillation performance can be reached also in the case of epitaxial garnet films of similar composition though the nature of trapping states acting in the transfer stage of the scintillation mechanism may be different. This is the first time that excellent scintillation properties were reproduced in epitaxial films. Lu3–xGdxGayAl5–yO12:Ce samples were grown by liquid phase epitaxy from BaO-B2O3–BaF2 flux and quantitatively compared with top performance bulk crystals as concerns light yield, energy resolution, scintillation decay, and afterglow characteristics. Reported characteristics point to the potential of such thin film scintillators in high resolution two-dimensional imaging and particle beam diagnostics.