Luminescence and energy transfer of white emitting phosphor Mg2Y2Al2Si2O12:Eu2+, Mn2+

Mechanistic insights for regulating the site occupancy, valence states and optical transitions of Mn ions in yttrium–aluminum garnets via codoping

“…Recently, Mn-doped garnets have been extensively studied for abundant site occupancy, diverse valence states, from Mn 2+ to Mn 6+ , and their distinct energy-level distributions with different optical transition behaviors. [8][9][10][11][12][13] Mn 2+ ions in solids have abundant site occupancy due to the near-spherical electronic distribution of the d 5 ground state, and the luminescence of the Mn 2+ activator ranges from green to deep red and even near-infrared (NIR). 2,[14][15][16] Mn 2+ doped Li 2 ZnGe 3 O 8 phosphors could be optionally tuned in the green to NIR region by controlling the occupation sites of Mn 2+ in different lattice sites.…”

“…Modifications on Y 3 Al 5 O 12 (YAG) garnets by co-substitution of Y-Al by Ca-Si or Mg-Si pairs can produce Mn 2+ to emit efficient red light. [10][11][12][13] Ca 2+ , Li + , Mg 2+ , Sr 2+ , Sc 3+ , and Na + dopants have been found to be beneficial for enhancing Mn 4+ luminescence in garnets. [29][30][31] Modern quantum theory of doping has been widely developed, 28 and the abundant experimental data for YAG:Mn form the basis of a systematical study of demonstrating the effectiveness of first-principles calculations in rationalizing the underlying mechanisms of regulating the site occupancy and valence state of activators via chemical conditions and codopants.…”

Elucidating the Multisite and Multivalence Nature of Mn Ions in Solids and Predicting Their Optical Transition Properties: A Case Study on a Series of Garnet Hosts

“…Mn-activated garnets have been extensively studied as important luminescence materials for phosphor-converted white light-emitting diodes, NIR emission, plant cultivation, and optical thermometric applications. − However, the manganese site occupancy, valence states, and optical transitions in garnets are controversial and not well resolved for abundant luminescence; − hence, it is desirable to elucidate these for the purpose of material design and optimization. Liu et al reported two Mn 2+ centers in the Ca 3 Sc 2 Si 3 O 12 host, where the red and NIR emissions were attributed to the dodecahedral and octahedral Mn 2+ by considering the covalency and crystal field effects .…”

Environment-Dependent Eu2+-Activated Ba3CaK(PO4)3 toward White-Light Emission by Chemical Cosubstitution of the (BO3)3– Anion Group

“…However, attributed to the overlapping spectra between different phosphors, the luminescence intensity, luminous efficiency, and color stability will be reduced under the influence of reabsorption. , To overcome these defects, white-light emission from single-phase phosphors can be a promising solution . Generally, white emission can be achieved by doping multiple activators and appropriately adjusting their proportion, such as Ba 3 Bi­(PO 4 ) 3 :Dy 3+ ,Eu 3+ , Mg 2 Y 2 Al 2 Si 2 O 12 :Eu 2+ ,Mn 2+ , and NaSrBi 2 (PO 4 ) 3 :Dy 3+ ,Sm 3+ . − Nevertheless, the energy-transfer process between doped activators and different thermal quenching (TQ) behaviors of various luminescent centers will lead to inevitable energy loss . Consequently, it is of great importance to promote the photoluminescence quality of WLEDs by investigating single-doped white-light-emitting phosphors.…”