Measurement of non-equilibrium carriers dynamics in Ce-doped YAG, LuAG and GAGG crystals with and without Mg-codoping

Abstract Non-linear absorption spectroscopy in pump and probe configuration has been used to test the population of non-equilibrium carriers in Ce-doped Y3Al5O12 (YAG), Lu3Al5O12 (LuAG), and Gd3AlxGa(5-x)O12 (GAGG) crystals with and without codoping by Mg2+ ions. A faster rise time of the induced optical density has been observed in all crystals codoped with Mg with respect to that in Mg-free samples. A significant difference in the time evolution of the differential optical density in GAGG with respect to YAG and LuAG crystals has also been measured. In both GAGG:Ce and GAGG:Ce,Mg an absorption band with maximum in the blue-green range and a decay time of 1.4 ps is present. This band is due to the absorption by free electrons before they are trapped or re-captured by Ce3+ ions. A broad absorption band in the yellow-red region with very short rise time and a decay time longer than 150 ps has been observed in all the Ce-doped garnets under study and can be attributed to the absorption from the Ce3+ excited states.

[1]  P. Rodnyi,et al.  Bandgap Engineering in Yttrium–Aluminum Garnet with Ga Doping , 2017 .

[2]  W. Moses.  Time of flight in PET revisited , 2003 .

[3]  Maurizio Conti,et al.  State of the art and challenges of time-of-flight PET. , 2009, Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics.

[4]  Vidmantas Gulbinas,et al.  Luminescence rise time in self-activated PbWO4 and Ce-doped Gd3Al2Ga3O12 scintillation crystals , 2016 .

[5]  Martin Nikl,et al.  Crystal Growth and Scintillation Properties of Ce Doped Single Crystals , 2022 .

[6]  R. D. Shannon.  Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides , 1976 .

[7]  Timing capabilities of garnet crystals for detection of high energy charged particles , 2017 .

[8]  L. Fu,et al.  Soft synthesis and vacuum ultraviolet spectra of YAG:Ce3+ nanocrystals: reassignment of Ce3+ energy levels , 2007 .

[9]  M. V. Nemallapudi,et al.  State of the art timing in TOF-PET detectors with LuAG, GAGG and L(Y)SO scintillators of various sizes coupled to FBK-SiPMs , 2016 .

[10]  O. Buganov,et al.  Dynamics of electronic excitations relaxation in hydrophilic colloidal CdS quantum dots in gelatin with involvement of localized states , 2016 .

[11]  Wai-Yim Ching,et al.  Electronic structure of yttrium aluminum garnet ( Y 3 Al 5 O 12 ) , 1999 .

[12]  V. Laguta,et al.  The Stable ${\rm Ce}^{4 + }$ Center: A New Tool to Optimize Ce-Doped Oxide Scintillators , 2016, IEEE Transactions on Nuclear Science.

[13]  E. Auffray,et al.  Effect of Mg2+ ions co-doping on timing performance and radiation tolerance of Cerium doped Gd3Al2Ga3O12 crystals , 2016 .

[14]  Xi-qi Feng,et al.  ESR and TSL study of hole and electron traps in LuAG:Ce,Mg ceramic scintillator , 2015 .

[15]  O. V. Bouganov,et al.  Ultrafast intramolecular charge separation in a donor-acceptor assembly comprising bis(η5-cyclopentadienyl)molybdenum coordinated to an ene-1,2-dithiolate-naphthalenetetracarboxylicdiimide ligand. , 2012, Inorganic chemistry.

[16]  P. Dorenbos,et al.  Evidence and Consequences of Ce $^{4+}$ in LYSO:Ce,Ca and LYSO:Ce,Mg Single Crystals for Medical Imaging Applications , 2013, IEEE Transactions on Nuclear Science.

[17]  A. Vedda,et al.  Band-gap engineering for removing shallow traps in rare-earth Lu3Al5O12 garnet scintillators using Ga3+ doping , 2011 .

[18]  M. Nikl,et al.  Crystal Growth and Scintillation Properties of Ce Doped ${\rm Gd}_{3}({\rm Ga},{\rm Al})_{5}{\rm O}_{12}$ Single Crystals , 2012, IEEE Transactions on Nuclear Science.

[19]  M. V. Nemallapudi,et al.  Sub-100 ps coincidence time resolution for positron emission tomography with LSO:Ce codoped with Ca , 2015, Physics in medicine and biology.

[20]  Fang Meng,et al.  Role of Ce4＋ in the Scintillation Mechanism of Codoped Gd3Ga3Al2O12∶Ce , 2014 .

[21]  W. Drozdowski,et al.  Studies of low temperature thermoluminescence of GAGG:Ce and LuAG:Pr scintillator crystals using the Tmax–Tstop method , 2014 .

[22]  E. Auffray,et al.  Free carrier absorption in self-activated PbWO 4 and Ce-doped Y 3 (Al 0.25 Ga 0.75 ) 3 O 12 and Gd 3 Al 2 Ga 3 O 12 garnet scintillators , 2016 .

[23]  Shunsuke Kurosawa,et al.  Defect Engineering in Ce-Doped Aluminum Garnet Single Crystal Scintillators , 2014 .

[24]  O. Buganov,et al.  Charge transfer process determines ultrafast excited state deactivation of thioflavin T in low-viscosity solvents. , 2010, The journal of physical chemistry. A.

[25]  W. Drozdowski,et al.  Studies of light yield as a function of temperature and low temperature thermoluminescence of Gd3Al2Ga3O12:Ce scintillator crystals , 2014 .

[26]  Paul Lecoq,et al.  Measurement of intrinsic rise times for various L(Y)SO and LuAG scintillators with a general study of prompt photons to achieve 10 ps in TOF-PET , 2016, Physics in medicine and biology.

[27]  Martin Nikl,et al.  Scintillator-oriented combinatorial search in Ce-doped (Y,Gd)3(Ga,Al)5O12 multicomponent garnet compounds , 2011 .

[28]  O. Buganov,et al.  Features of Raman amplification in KGW and barium nitrate crystals at excitation by femtosecond pulses , 2012 .