Crystal growth and luminescence properties of Lu0.8Sc0.2BO3 scintillators doped with different Ce concentrations

Transparent Lu0.8Sc0.2BO3:Ce single crystals doped with different Ce concentrations were grown by the Czochralski method. X-ray diffraction measurements showed that the as-grown crystals all possessed hexagonal structure with R 3 ¯ c space group. The more initial Ce ion doping content in Lu0.8Sc0.2BO3:Ce, the smaller effective segregation coefficient of Ce in crystal will be, confirmed by the inductively coupled plasma atomic emission spectrometry (ICP-AES) tests. The Ce3+ 5d → 4f emission band and five excitation states were both observed in the photoluminescence spectra (PL). The increase of luminescence center in crystal or the concentration quenching exerts effects in the change of PL decay time, depending on the cerium concentration. The radioluminescence spectra showed that the Lu0.8Sc0.2BO3:Ce crystals had one broad emission band corresponding to the 5d → 4f transition of Ce3+ ions, similar to their PL spectra. Consequently, we found that Lu0.8Sc0.2BO3:2 at.%Ce crystal achieved the maximum scintillation efficiency and for Lu0.8Sc0.2BO3:3 at.%Ce crystal, there might be already affected by a concentration quenching effect.