Energy of the first 4f7→4f65d transition of Eu2+ in inorganic compounds

Luminescent properties of Eu2+ and Ce3+ ions in strontium litho-silicate Li2SrSiO4

“…In all the cases the emission bands are broad and the corresponding Stokes shifts are very large, ranging from $ 7500 cm À 1 for BaSiO 3 :Eu 2 + , Sr 2 LiSiO 4 F:Eu 2 + and up to 12,000 cm À 1 for Ba 2 Mg(BO 3 ) 2 :Eu 2 + . Poort et al [20,21] and later Dorenbos [22] pointed out that these long-wavelength emissions are possibly not related to the 4f 6 5d-4f 7 transitions of Eu 2 + ions, but may be due to an absolutely different process, namely radiative decay of an impurity trapped exciton. This interpretation implies that excitation into the Eu 2 + 4f 7 -4f 6 5d bands leads to ionization of Eu 2 + ions and the formation of an exciton-like state, which consists of a bound electron hole pair with the hole localized on the Eu 3 + ion and the electron delocalized on the nearest-neighbor cations.…”

d–f luminescence of Ce3+ and Eu2+ ions in BaAl2O4, SrAl2O4 and CaAl2O4 phosphors

“…The effect of the host crystal on this energy difference is expressed by the red shift D and the Stokes shift S  . The energy of f →d absorption and that of the d→f emission can be written respectively, as [33]:…”

Liquid Phase Precursor driven approach for the synthesis of Ca–Sr–Ba orthosilicate phosphors for white LED applications

“…The absorption band observed is due to the 4f 7 ( 8 S 7/2 ) 4f 6 5d transition of the Eu 2+ ions. 18) The absorption bands extend into a wide wavelength region due to the effect of crystal field on the 5d orbitals of Eu 2+ ion. In the emission spectra the distinct difference in the emission band and intensity is observed depending on the excitation wavelength due to the transition of Eu 2+ ion and presence in lattice site identified as Sr 2+ site of nine coordination.…”