Decay of the Ce3+ luminescence of LaMgAl11O19 : Ce3+ and of CeMgAl11O19 activated with Tb3+ or Eu3+

Ce3+ Luminescence in Hexagonal Aluminates Containing Large Divalent or Trivalent Cations

“…Our last subject is the discussion of the quantum efficiencies of Cea+-activated aluminates. Recent estimates (8) indicate that the energy transfer between Ce 3+ ions is ineffective; the absence of concentration quenching in the systems considered confirms this opinion. The ineffective energy transfer in the Ce a+activated phosphors has the effect that in such materials the quenching of the luminescence by unintentionally introduced defects is generally less drastic than in the corresponding Eu 2+ phosphors in which the Eu2+-Eu 2+ transfer efficiency was observed to be high.…”

Identifying the Emission Centers and Probing the Mechanism for Highly Efficient and Thermally Stable Luminescence in the La3Si6N11:Ce3+ Phosphor

“…Obviously, an efficient energy transfer from Ce La(1) to Ce La(2) should be responsible for this situation because the Ce 3+ concentration variation is unable to induce such large changes in energy-level distributions. Generally, an efficient energy transfer always occurs between different ion species, such as Ce 3+ –Tb 3+ , Eu 2+ –Mn 2+ , Bi 3+ –Eu 3+ , etc., − but rarely reported in the same ion species.…”

“…The inherent natures are highly related to the structural rigidity, which can be characterized by Debby temperature (Θ D ). − As a large Θ D value indicates that high-energy phonon modes are inaccessible, the number of nonradiative relaxation pathways decreases, thereby leading to highly efficient emission. Additionally, the activators accepting energy from sensitizers or host matrix is another way to promote the emission efficiency of luminescence centers, which is common in many commercial phosphors, such as CeMgAl 11 O 19 :Tb 3+ , (La,Ce)­PO 4 :Tb 3+ , BaMgAl 10 O 17 :Eu 2+ ,Mn 2+ , Y 2 O 3 :Bi 3+ ,Eu 3+ , etc. − Also, nearly all these efficient energy transfers occur between different ion species due to their spectral overlap.…”

Combustion Synthesis of Hexaaluminate Phosphors

“…Although efficient Ce 3+ emission has been reported from the endmember compound CeMgAl 11 O 19 by Sommerdijk and Verstegen, 14 a substitution of only 0.1 Tb 3+ cations was apparently sufficient to induce complete excitation transfer from the Ce 3+ cation to the Tb 3+ cation. The decay times and mechanism of excitation transfer were investigated in some detail by Sommerdijk et al, 15 who concluded that a dipole-quadrapole interaction was necessary.…”