Life-time resolved emission spectra in CdBr2 crystals

Decay curves of the Y-emission were measured at 60, 100 and 140 K by varying emission energy in the range of the Y-emission. The observed decay curves were decomposed into three or four exponential decay components. These decay components were named τ1, τ2, τ4 and τ5. The emission spectrum for each decay component, i.e., life-time resolved emission spectrum, was obtained by analyzing the observed decay curves. At 60 K, three bands at 1.95, 2.24 and 2.47 eV are obtained for the τ5, τ4 and τ1 components, respectively. For the τ2 component, sharp peaks appear around 2.30-2.50 eV. At 100 K, a dominant band of the τ4 component is seen at 2.25 eV. In the low-energy side, a weak band of the τ5 component is located at 1.95 eV. At 140 K, only a single band of the τ4 component is observed at 2.27 eV. The origin of emission bands in life-time resolved emission spectra is discussed.