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

Abstract

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 5D0→7F2 transitions of Eu3+ in C2 site. It is worth mentioning that several emission peaks between 575 and 605 nm mainly ascribe to the transitions of different 5D0 levels to the split 7F1 levels of Eu(C2) or Eu(C3i). 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+(C3i) and Eu3+(C2), respectively. The XEL strongest emission of Lu2O3:Eu sample is around 612 nm with a bright red luminescence that matches silicon photodetectors sensitivity.

Effects of Preparation Atmosphere and Doping Concentration on Scintillation and Photoluminescence Properties of Lu2O3:Eu Scintillation Single Crystals

“…Single crystal growth of Lu 2 O 3 is a great challenge due to its super high 2400 • C melting point [23]. Several single crystal preparation methods are adopted to prepare the Lu 2 O 3 single crystal, such as Czochralski (CZ) [23], the heat exchanger method (HEM) [24], the Bridgman method [25], laser-heated pedestal growth (LHPG) [26], the micro-pulling-down (m-PD) method [27], etc. The scintillation single crystal is the essential application form of a scintillator due to its higher transparency and excellent scintillation performance [28][29][30].…”