First-principles search for efficient activators for LaI3

摘要: Abstract First-principles calculations were performed using density functional theory with Hubbard corrections or hybrid exchange-correlation functionals, as well the GW approximation, to predict dopants that could serve efficient activators for LaI 3 , a potentially very bright scintillator which an appropriate activator has not been identified yet. The considered in this work included series of lanthanide ions (Ce, Pr, Nd, Eu, Gd, and Tb) several n s 2 (Tl, Pb, Bi, Sb). Based on both ground-state constrained DFT simulate excited states, trivalent shown constitute improvement over Ce 3+ experimental data exist, they showed occupied 4f states below valence band maximum (VBM) 5d above conduction (CBM). In contrast, only divalent considered, Eu 2+ displayed within gap host, but its calculated be CBM. nonetheless exploited by increasing energy slightly through substitution iodide bromide ions. Similar results obtained Tl + . Finally, Bi Sb predicted virtue having unoccupied p CBM, can electron traps combine holes at VBM form localized luminescence centers. Therefore, Bi- Sb-doped should grown tested experimentally. Comparison empirical relationships relative positions levels rare-earth implications doping schemes scintillation mechanisms are also discussed.