Shenhua Jiang

Tunable emission, energy transfer and charge compensation in Sr3(VO4)2:Sm3+,P5+,Na+ phosphor

A series of Sr3(VO4)2:Sm(3+),P(5+),Na(+) phosphors are synthesized by using solid-state reaction method in air. The strongest emission band peaking at ∼600 nm is assigned to the (4)G5/2→(6)H7/2 transition of Sm(3+) ion, and the strong excitation peak at ∼402 nm due to (6)H5/2→(4)F7/2 transition indicates that these phosphors can be excited by near ultraviolet light emitting diode chip. Energy transfer (ET) between VO4(3-) group and Sm(3+) ion can be observed. Sr3(VO4)2:Sm(3+) phosphor with excitation 320 nm exhibits a systematically varied hues from green to yellow by changing Sm(3+) ion concentration from 0 to 6 mol%. The luminous mechanism of Sr3(VO4)2:Sm(3+) phosphor is explained by using the energy level diagrams of VO4(3-) group and Sm(3+) ion. The luminescence properties of Sr3(VO4)2:Sm(3+) phosphor can be improved and tuned by codoping the P(5+) and Na(+) ions due to ET and charge compensation. Lifetimes of Sr2.925Sm0.05(VO4)2, Sr2.925Sm0.05(V0.9P0.1O4)2, and Sr2.9Na0.05Sm0.05(V0.9P0.1O4)2 phosphors are 1.208, 1.219, and 0.796 ms, respectively. The experiment results are helpful to adjust the luminescence properties of Sm(3+)-doped other phosphors.

Tunable emission, energy transfer and charge compensation in SrMoO4:Sm(3+),Tb(3+),Na(+) phosphor.

A series of SrMoO4:Sm(3+),Tb(3+),Na(+) phosphors was synthesized using a high-temperature solid-state reaction method in air. On excitation at 290 nm, SrMoO4:Sm(3+),Tb(3+) phosphor emitted light that varied systematically from green to reddish-orange on changing the Sm(3+) and Tb(3+) ion concentrations. The emission intensities of SrMoO4:Sm(3+) and SrMoO4:Sm(3+),Tb(3+) phosphors were increased two to four times due to charge compensation when Na(+) was added as a charge compensator. The luminescence mechanism and energy transfer could be explained using energy-level diagrams of the MoO4(2-) group, Sm(3+) and Tb(3+) ions. SrMoO4:Sm(3+),Tb(3+),Na(+) could be used as reddish-orange phosphor in white light-emitting diodes (LEDs) based on an ~ 405 nm near-UV LED chip. This research is helpful in adjusting and improving the luminescence properties of other phosphors.

Enhanced emission of CaNb2O6 : Sm3+ phosphor by codoping Na+/B3+ and the emission properties

A series of CaNb2O6:xSm3+ (0 ≤x≤ 10 mol%) and CaNb2O6 : Sm3+, Na+/B3+ phosphors were synthesized by the solid-state reaction method in air. Their crystal structures and luminescence properties were investigated and analysed, respectively. Host CaNb2O6 emitted blue light with excitation 270 nm. CaNb2O6:xSm3+ phosphors showed a systematically varied hue from blue to white by changing Sm3+ ion concentration from 0 to 10 mol% with excitation of 270 nm and their chromaticity coordinates were the regions from (0.1665, 0.1767) to (0.2484, 0.2260). Luminescence properties of CaNb2O6 : Sm3+ phosphor were tuned and improved significantly by codoping B3+ or Na+ ions. Energy transfer between Nb2O62−

Luminescence properties of Ca3Ti2O7:Eu3+, Bi3+, R+ (R+=Li+, Na+, and K+) red emission phosphor

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Synthesis and luminescence properties of Li2SnO3:Mn4+ red-emitting phosphor for solid-state lighting

group and Sm3+ ion was observed and analysed via luminescence properties. The luminous mechanism was explained by energy level scheme and energy transfer process in CaNb2O6 : Sm3+ phosphor. The strong excitation band peaking at ∼407 nm indicated that the CaNb2O6 : Sm3+, Na+/B3+ phosphor has a potential application in white light-emitting diodes based on near-UV LED chip.