The effect of intrinsic defects on garnet scintillator performance

Band-Gap and Band-Edge Engineering of Multicomponent Garnet Scintillators from First Principles

“…These optimization efforts have relied on the manipulation of the garnet electronic structure through admixing, and * syadav@lanl.gov, yadav.satyesh@gmail.com in the process creating so-called "multicomponent" garnets [17]. It is well-known that cation antisite defects are present in garnets (RE 3+ on Al 3+ sites and vice versa) [18][19][20][21][22][23] and that they contribute to reduced scintillator performance [24] by creating traps for the electronic carriers which results in considerable slowing down of scintillation response. However, the challenge of removing cation antisite defects in garnet is that they are isovalent (i.e.…”

Band-gap engineering for removing shallow traps in rare-earth Lu3Al5O12garnet scintillators using GaFasoli1, Vedda2, Nikl3 et al. 2011Phys. Rev. B2964982View full textAdd to dashboardCite

“…Recently, thermally stim- * Electronic address: stanek@lanl.gov ulated luminescence (TSL) experiments confirmed the presence of defect-induced shallow traps in LuAG:Ce [6], which are responsible for degraded scintillation performance [7]. Furthermore, antisites were determined to be the lowest energy defect present in a range of aluminate garnets via atomistic simulation [8][9][10][11], providing additional support for the presence of this type of defect. Recognizing cation antisites as the defect responsible for degraded scintillator performance, the next step is to remove these defects, or at least reduce the degree of electron trapping (and corresponding delayed scintillation) associated with them.…”

Electronic structure of Ce3+ multicenters in yttrium aluminum garnets

“…However, in Czochralski grown bulk crystals, so called antisites are also found, i.e., rare-earth ions replacing aluminum in sites with octahedral symmetry. 12 In addition, other types of rare-earth and transition metal centers occur often in garnets. 13 On the other hand, the YAG layers epitaxially grown from flux do not contain antisites of rare-earths.…”