Crystal growth and characterization of rare earth iodides for scintillation detection

In this paper we report on the crystal growth and characterization of a new class of inorganic scintillators based on the rare earth iodides, in particular LuI3, YI3 and GdI3, doped with trivalent cerium. Single crystals of LuI3:Ce3+, YI3:Ce3+ and GdI3:Ce3+ were grown by the vertical Bridgman technique in evacuated silica ampoules. In some cases, tantalum or graphite crucibles were used to minimize wetting of the ampoule. X-ray excited optical luminescence spectra of LuI3:Ce3+, YI3:Ce3+ and GdI3:Ce3+ exhibit a broad band due to Ce-3 + emission, peaking in the 500-550 nm region. LuI3:Ce3+, YI3:Ce3+ and GdI3:Ce3+ show high light yields up to 100,000 photons/MeV and fast principle decay time constants of <40ns. Energy resolutions measured at 662keV are of the order of 3.5-9% (FWHM). (c) 2007 Elsevier B.V. All rights reserved.