Structure, luminescence and energy transfer in Ce³⁺ and Mn²⁺ codoped γ-AlON phosphors

Abstract

Upon UV or blue light excitation, the codoped γ-AlON phosphor has higher luminescence intensity, quantum efficiency and thermal stability than the Mn2+-doped γ-AlON due to energy transfer and low total concentration of Ce3+ and Mn2+ ions.

A novel red-emitting phosphor Mg2Y2Al2Si2O12:Ce3+/Mn2+ for blue chip-based white LEDs

“…The experiment verified the relevant information, and a large number of studies reported that Ce 3+ transfers energy to Mn 2+ and examples of Mn 2+ ion transferring energy to Ce 3+ have not been found. 34–39 Furthermore, the experiment measured the lifetime change of Mn2 luminescence center with Ce 3+ doping, as shown in Fig. 9(b) .…”

Unraveling the Eu2+ → Mn2+ Energy Transfer Mechanism in w-LED Phosphors

“…With reference to each other or sometimes to an original paper by Dexter and Schulman, it is stated that these ratios are expected to increase with the Mn 2+ concentration C proportional to C 6/3 (dipole–dipole), C 8/3 (dipole–quadrupole), or C 10/3 (quadrupole–quadrupole). Often the best fit was obtained for C 8/3 , and a dipole–quadrupole ET mechanism was thus concluded. − Sometimes a better fit was found for C 6/3 or C 10/3 and was used to derive that dipole–dipole or quadrupole–quadrupole interaction was the operative transfer mechanism. ,− Finally, it is important to realize that these C S /3 vs I S0 / I S , η S0 /η S , or τ S0 /τ S fitting methods to derive ET mechanisms are also widely used for other donor–acceptor pairs, for example, Tb 3+ → Eu 3+ . The C S /3 model is widespread but, as will be shown below, incorrect for donor–acceptor energy transfer as it has been derived for concentration quenching by energy migration among donors.…”

“…Absorption transitions from the 6 A 1 ground state to the 4 T 1 and 4 T 2 excited states of Mn 2+ are spin- and parity-forbidden. To tackle the weak d–d absorption, codoping with sensitizers having allowed transitions (f–d in Eu 2+ , Ce 3+ ; s–p in Sn 2+ , Sb 3+ , Pb 2+ , Bi 3+ ) with effective absorption of blue excitation light can be the solution if efficient nonradiative energy transfer to Mn 2+ ions can be realized. − …”

“…Sensitized Mn 2+ emission has widely been investigated in many host matrices. − The mechanism for Ce 3+ –Mn 2+ and Eu 2+ –Mn 2+ energy transfer is not clear: both electric dipole–quadrupole and Dexter exchange interaction have been proposed . As electric dipole transitions are strongly forbidden in Mn 2+ , dipole–dipole interaction is considered as inefficient.…”

Thermally Robust and Color-Tunable Blue-Green-Emitting BaMgSi4O10:Eu2+,Mn2+ Phosphor for Warm-White LEDs

“…A similar situation can also be found in Ce 3+ -Mn 2+ codoped γ-AlON phosphor. 35 The η T is possible to be further increased by increasing Mn 2+ doping concentration, but the increasing concentration quenching of Mn 2+ may result in low emission efficiency as well.…”