Ce concentration dependence of optical and scintillation properties on Ce-doped La2Si2O7crystal

Abstract

A lanthanum pyrosilicate (La2Si2O7, LaPS) single crystal is successfully grown with a Ce-doped concentration of 0.5 to 20.0% as well as undoped LaPS for reference. The photoluminescence emission map of Ce-doped LaPS has broad emission at 360-410 nm from Ce3+ 5d-4f transition, with a decay time of 20-24 ns. In the scintillation properties, Ce-doped LaPS presents the scintillation peak at 390 nm under X-ray excitation, with the decay time constant at 26-31 ns plus another decay constant caused by the emission from host material at 250-600 ns. The afterglow level at 20 ms after X-ray irradiation is around 30-56 ppm. In the 662 keV γ-ray pulse height spectra, 1.0% Ce-doped LaPS shows a clear photoabsorption peak, with a scintillation light yield of 5400 ph MeV-1. The relationship between γ-ray energy and the photoabsorption peak channel (linearity) is also covered in this study.