Defect Engineering in SrI2:Eu2+ Single Crystal Scintillators

Eu2+-activated strontium iodide is an excellent single crystal scintillator used for gamma-ray detection, and significant effort is currently focused on the development of large-scale crystal growth techniques. A new approach of molten-salt pumping or so-called melt aging was recently applied to optimize the crystal quality and scintillation performance. Nevertheless, a detailed understanding of the underlying mechanism of this technique is still lacking. The main purpose of this paper is to conduct an in-depth study of the interplay between microstructure, trap centers, and scintillation efficiency after melt aging treatment. Three SrI2:2 mol % Eu2+ single crystals with 16 mm diameter were grown using the Bridgman method under identical growth conditions with the exception of the melt aging time (e.g., 0, 24, and 72 h). Using energy-dispersive X-ray spectroscopy, it is found that the matrix composition of the finished crystal after melt aging treatment approaches the stoichiometric composition. The mecha...

[1]  M. Taylor.  Preparation of Anhydrous Lanthanon Halides. , 1962 .

[2]  V. R. Honnold,et al.  Thermal activation energies in lithium fluoride, sodium fluoride, and sodium chloride crystals , 1967 .

[3]  R. Feigelson,et al.  Vertical bridgman growth of CdGeAs2 with control of interface shape and orientation , 1980 .

[4]  S. McKeever.  Thermoluminescence of solids: Contents , 1985 .

[5]  G. Meyer,et al.  The ammonium-bromide route to anhydrous rare earth bromides MBr3 , 1987 .

[6]  R. Zhu,et al.  Light attenuation length of barium fluoride crystals , 1993 .

[7]  P. Rudolph,et al.  Distribution and genesis of inclusions in CdTe and (Cd,Zn)Te single crystals grown by the Bridgman method and by the travelling heater method , 1995 .

[8]  O. Wijk,et al.  Investigation of the dehydration schemes of NdCl3-6H2O, TbQ3·6H2O and DyCl3·6H2O using a fluidized bed , 1997 .

[9]  R. Muenchausen,et al.  Thermally stimulated luminescence from x-irradiated porous silicon , 1997 .

[10]  K. Masumoto,et al.  Growth of AgGaS2 single crystals by a self-seeding vertical gradient freezing method , 1998 .

[11]  Tuviah E. Schlesinger,et al.  Study of impurity segregation, crystallinity, and detector performance of melt-grown cadmium zinc telluride crystals , 2002 .

[12]  A. Vedda,et al.  Energy transfer and storage processes in scintillators: The role and nature of defects , 2007 .

[13]  Arnold Burger,et al.  Strontium and barium iodide high light yield scintillators , 2008 .

[14]  He Feng,et al.  Annealing effects on Czochralski grown Lu2Si2O7:Ce3+ crystals under different atmospheres , 2008 .

[15]  H. Fang,et al.  Reducing Melt Inclusion by Submerged Heater or Baffle for Optical Crystal Growth , 2008 .

[16]  A. Burger,et al.  New Scintillator Materials (K2CeBr5) and (Cs2CeBr5) , 2008 .

[17]  P. Dorenbos,et al.  Advances in Yield Calibration of Scintillators , 2008, IEEE Transactions on Nuclear Science.

[18]  Woon-Seng Choong,et al.  Crystal Growth and Scintillation Properties of Strontium Iodide Scintillators , 2009, IEEE Transactions on Nuclear Science.

[19]  Jarek Glodo,et al.  Concentration Effects in Eu Doped SrI $_{2}$ , 2010, IEEE Transactions on Nuclear Science.

[20]  Hongsheng Shi,et al.  The LaBr3:Ce Crystal Growth by Self-Seeding Bridgman Technique and Its Scintillation Properties , 2010 .

[21]  H. Tan,et al.  Modeling scintillation light absorption and re-emission in SrI2(Eu) scintillators , 2011 .

[22]  P. Dorenbos,et al.  Scintillation Properties of and Self Absorption in ${\rm SrI}_{2}\!:\!{\rm Eu}^{2+}$ , 2011, IEEE Transactions on Nuclear Science.

[23]  Owen B. Drury,et al.  Effects of Packaging SrI2(Eu) Scintillator Crystals , 2011 .

[24]  K. Kamada,et al.  Deep trapping states in Cerium doped (Lu,Y,Gd)3(Ga,Al)5O12 single crystal scintillators , 2012, 1211.1256.

[25]  Charles L. Melcher,et al.  Scintillation kinetics and thermoluminescence of SrI2:Eu2+ single crystals , 2012 .

[26]  I. N. Ogorodnikov,et al.  A luminescence spectroscopy study of scintillation crystals SrI2 doped with Eu2 , 2012 .

[27]  Anatoli I. Popov,et al.  Luminescence and ultraviolet excitation spectroscopy of SrI2 and SrI2:Eu2+ , 2013 .

[28]  R. T. Williams,et al.  First principles calculations and experiment predictions for iodine vacancy centers in SrI2 , 2013 .

[29]  A. Vedda,et al.  Defect-Driven Radioluminescence Sensitization in Scintillators: The Case of Lu2Si2O7:Pr , 2013 .

[30]  Arnold Burger,et al.  Bridgman bulk growth and scintillation measurements of SrI2:Eu2+ , 2013 .

[31]  Michael Groza,et al.  Bridgman growth of large SrI2:Eu2+ single crystals: A high-performance scintillator for radiation detection applications , 2013 .

[32]  M. Allix,et al.  Light yield sensitization by X-ray irradiation of the BaAl4O7:Eu(2+)ceramic scintillator obtained by full crystallization of glass. , 2014, Physical chemistry chemical physics : PCCP.

[33]  B. Sadigh,et al.  Origin of resolution enhancement by co-doping of scintillators: Insight from electronic structure calculations , 2014, 1404.6554.

[34]  S. Friedrich,et al.  The europium oxidation state in CsSrI3:Eu scintillators measured by X-ray absorption spectroscopy , 2014 .

[35]  S. Motakef,et al.  Impurity segregation in zone-refined precursors for crystalline halide scintillators , 2015 .

[36]  J. A. Kolopus,et al.  Divalent europium doped and un-doped calcium iodide scintillators: Scintillator characterization and single crystal growth , 2015 .

[37]  A. Yoshikawa,et al.  Recent R&D Trends in Inorganic Single‐Crystal Scintillator Materials for Radiation Detection , 2015 .