Photoluminescence and scintillation properties of Ce-doped CaBr2 crystals

Ce-doped CaBr2 crystals were evaluated for photoluminescence (PL) and scintillation properties. The samples showed PL peaking at 370 and 400 nm and decay time constants of 22 ns, which were due to 5d–4f transitions of Ce3+ ions. The PL maximum quantum yield was 66.1% in the 1% Ce-doped sample upon excitation at 340 nm. Under X-ray irradiation, the samples showed an emission peak at 400 nm due to the 5d–4f transitions of Ce3+ ions. The 0.1% Ce-doped sample showed intrinsic emission at around 590 nm as well. From the scintillation decay curves, the two components with decay time constants of ∼20 and 200–400 ns were obtained. Their origins would be attributed to the 5d–4f transitions of Ce3+ ions and intrinsic emission, respectively. From the pulse height spectra, the light yield of the 0.1% Ce-doped sample was 50 ph/5.5 MeV-α.