Effects of Ce3+ substitution on the local structure of cerium and scintillation properties of CLLBC:Ce crystals

Achieving Superior n/γ Discrimination and Luminescent Thermal Stability in Cs2LiLaBr6 Single Crystals by High Concentration Ce3+ Doping

“…The X-ray-induced radioluminescence spectra of Cs 2 LiLaBr 6 :x mol % Ce (x = 1, 2, 10) samples are recorded and shown in Figure 1d. As previously reported, 13 Ce 3+ has been confirmed to occupy two lattice sites in the CLLB host. Three main emission peaks of 355, 386, and 420 nm are observed; the former corresponds to Ce1 5d→ 4f luminescence while the latter two correspond to the 5d→ 4f 12 F 5/2 and 5d→ 4f 12 F 7/2 transition emission of Ce2, respectively (Ce1 is defined as the Ce 3+ ion occupying the Cs + lattice while Ce2 is corresponding to the La 3+ lattice).…”

“…It is slightly higher than the theoretical Ce 3+ concentration. As previous work reported, 13 the segregation coefficient of Ce 3+ is about 1.4 in the CLLB crystal. Therefore, it is rational that the concentration of Ce 3+ will be preferentially enriched in the crystalline head and diffused to the tail with the gradual growth of the crystal.…”

“…The thermal quenching temperature is around 360 K for CLLB:1 mol % Ce crystal, while it exceeds 460 K for CLLB:10 mol % Ce crystal. It probably results from two factors, namely, the enhancement of self-absorption effect due to overlap between excitation and emission bands of Ce centers and an increased energy transfer probability from Ce1 to Ce2 . In a word, the CLLB:10 mol % Ce crystal presents an excellent thermal stability, which has a great advantage in the extreme environment application.…”

“…11,12 Therefore, the scintillation characteristics of the crystal can be improved by adjusting the doping concentration of Ce 3+ to change its location environment and electronic band structure in the crystal. Previous work reports that the Ce 3+ is likely to replace both Cs + and La 3+ sites in the lattice, 13 and the replaced proportion of these two sites is closely related to the Ce 3+ doping concentration. However, this substitution can lead to compositional disorder in the matrix structure.…”

“…As the luminescent centers of the CLLB crystal, Ce 3+ concentration could significantly affect the scintillation properties. , In general, the splitting of 5d levels of Ce 3+ is strongly dependent on the location environment and electronic band structure. , Therefore, the scintillation characteristics of the crystal can be improved by adjusting the doping concentration of Ce 3+ to change its location environment and electronic band structure in the crystal. Previous work reports that the Ce 3+ is likely to replace both Cs + and La 3+ sites in the lattice, and the replaced proportion of these two sites is closely related to the Ce 3+ doping concentration. However, this substitution can lead to compositional disorder in the matrix structure.…”