研究業績

K2Cu(Cl,Br)3 crystals were prepared by the slow cooling method and evaluated for photoluminescence (PL) and scintillation properties. PL emission and scintillation peaks due to the recombination of excitons were observed at 400 nm. The PL quantum yields were estimated to be 61.0% for K2CuCl3, 72.7% for K2Cu(Cl0.5,Br0.5)3, and 75.8% for K2CuBr3, respectively. The scintillation decay curves were approximated by a single exponential function model, and the calculated decay time constants were 14–60 μs. The afterglow levels at 20 ms passed after X-ray irradiation were obtained to be 5–1225 ppm. The light yields of K2CuCl3 and K2Cu(Cl0.5,Br0.5)3 were 7700 and 9900 photons MeV−1 when calculated from the pulse height spectra under 137Cs γ-ray (662 keV) irradiation.