Highly efficient far-red emitting Mn4+-activated Li3La3W2O12 phosphors for plant growth LED lighting

An efficient rare-earth free deep red-emitting GdGeSbO6:Mn4+ phosphor for white light-emitting diodes

“…23–27 The 3d 3 electronic configuration of Mn 4+ ions replaced Al 3+ , Si 4+ , Ge 4+ , Nb 5+ , Sb 5+ , Ta 5+ , W 6+ , and Mo 6+ in the octahedral crystal structure with the splitting of its electronic shell layer into triple-simple t 2g and double-simple states, resulting in three outermost electrons occupying the lower-energy t 2g orbitals, stabilizing the Mn 4+ ions at the lowest energy level and producing the typical 2 E g → 4 A 2g transition, 28,29 which gives rise to emission spectra in the 620–780 nm region. 30–32 Huang 33 has prepared Li 3 La 3 W 2 O 12 :Mn 4+ (∼719 nm) 34 and Ca 3 Al 4 ZnO 10 :Mn 4+ ,Mg 2+ (∼714 nm) phosphors, which exhibit high IQE, but their thermal stability is suboptimal; conversely, Hu has developed Li 2 MgTi 3 O 8 :Mn 4+ (∼680 nm) 35 and Li 2 Mg 3 TiO 6 :Mn 4+ (∼675 nm) 36 that exhibit better thermal stability but lower IQE. Therefore, the development of Mn 4+ doped oxide phosphors with high IQE and thermal stability is necessary.…”

Defect compensation and intervalence charge transfer state-based Pr3+-doped niobate antithermal quenching phosphors

“…Rare earth fluorescent materials are widely employed in various fields, such as everyday illumination, electronic displays, and solid-state lasers, due to their energy-saving, environmentally friendly, and highly efficient characteristics. [1][2][3][4][5][6] However, thermal quenching at high temperatures leads to a decrease in luminescence intensity and chromaticity shift, which seriously limits its application in the high-temperature field. [7][8][9][10][11] Therefore, various strategies have been developed to enhance the antithermal quenching performance of phosphors, including defect engineering, energy transfer processes, and structural rigidity improvement.…”