Single Crystal Preparation and Luminescent Properties of Lu2O3:Eu Scintillator by Vertical Bridgman Method

Europium-doped lutetium oxide (Lu2O3:Eu) single crystal is grown by vertical Bridgman method for the first time. Correlated measurements of X-ray diffraction, X-ray fluorescence spectra, optical transmittance, photoluminescence excitation, photoluminescence (PL), PL decay, and X-ray excited luminescence (XEL) spectra are performed. The transmittance of about 80% above 300 nm indicates that the crystal is of good optical quality. By measuring actual Eu3+ concentration, the effective segregation coefficient of Eu3+ in the Lu2O3:Eu crystal is calculated to be 0.75. In the PL spectrum, the dominant emission peaks at 612 and 630 nm originate from the D-5(0)-> F-7(2) transitions of Eu3+ in C-2 site. It is worth mentioning that several emission peaks between 575 and 605 nm mainly ascribe to the transitions of different D-5(0) levels to the split F-7(1) levels of Eu(C-2) or Eu(C-3i). PL decay spectra indicate the decay time of 612 nm emission can be determined about 1.0 ms. The decay curve of 582.6 nm emission can be fitted into triple components, and the 5.3 and 1.4 ms components are attributed to Eu3+(C-3i) and Eu3+(C-2), respectively. The XEL strongest emission of Lu2O3:Eu sample is around 612 nm with a bright red luminescence that matches silicon photodetectors sensitivity.