Luminescent properties and particle morphology of Ca3(PO4)2:Gd3+, Pr3+ phosphor powder prepared by microwave assisted synthesis

Sivaramaiah²,

et al. 2019

Bull Mater Sci

A BaAl 2 O 4 :Gd 3+ phosphor was successfully prepared using a combustion technique. An X-ray diffraction pattern was used to characterize the resultant phosphor, and the photoluminescence (PL) of the prepared BaAl 2 O 4 :Gd 3+ was studied. Under a 273-nm excitation, the main emission peak of the phosphor is located at 314 nm, and this is attributed to the 6 P 7/2 → 8 S 7/2 transition of Gd 3+. Electron paramagnetic resonance (EPR) spectrum appears to be U-shaped, and lines are evident at g eff ∼ 2.14, 4.56 and 6.75. The PL and EPR analyses indicate the presence of Gd as Gd 3+ in this sample.

Section: Introductionmentioning

confidence: 99%

Ultraviolet B emission from a $$\hbox {Gd}^{3+}$$ Gd 3 + -doped $$\hbox {BaAl}_{2}\hbox {O}_{4}$$

Sivaramaiah²,

et al. 2019

Bull Mater Sci

“…Compared with the sample without Bi 3+ , the weaker wide emission located around 440 nm resulted from the 6s 2 →6s6p transitions of Bi 3+ ions. According to the photoluminescence excitation (PLE) spectra of these YGB phosphors in Figure 5 c, monitored at 313 nm, the strongest excitation band centered at 273 nm should be attributed to the 8 S 7/2 → 6 I J transition of the Gd 3+ ion, which well overlaps with the 253.7 nm line of mercury lamps [ 35 ], while the emission peak at 440 nm was derived from the 3 P 1 → 1 S 0 transition of Bi 3+ ions [ 36 ]. In particular, Figure 5 d shows the PLE spectra of YGB samples with different Gd 3+ contents in monitoring the 440 nm emission, the intensity of which decreases with the Gd 3+ content, illustrating the energy transfer (ET) from Bi 3+ to Gd 3+ ions that consumes the excitation energy of Bi 3+ ions.…”

Section: Resultsmentioning

confidence: 99%

Narrow UVB-Emitted YBO3 Phosphor Activated by Bi3+ and Gd3+ Co-Doping

Yang

Sun

2023

Nanomaterials

Y0.9(GdxBi1−x)0.1BO3 phosphors (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0, YGB) were obtained via high-temperature solid-state synthesis. Differentiated phases and micro-morphologies were determined by adjusting the synthesis temperature and the activator content of Gd3+ ions, verifying the hexagonal phase with an average size of ~200 nm. Strong photon emissions were revealed under both ultraviolet and visible radiation, and the effectiveness of energy transfer from Bi3+ to Gd3+ ions was confirmed to improve the narrow-band ultraviolet-B (UVB) (6PJ→8S7/2) emission of Gd3+ ions. The optimal emission was obtained from Y0.9Gd0.08Bi0.02BO3 phosphor annealed at 800 °C, for which maximum quantum yields (QYs) can reach 24.75% and 1.33% under 273 nm and 532 nm excitations, respectively. The optimal QY from the Gd3+-Bi3+ co-doped YGB phosphor is 75 times the single Gd3+-doped one, illustrating that these UVB luminescent phosphors based on co-doped YBO3 orthoborates possess bright UVB emissions and good excitability under the excitation of different wavelengths. Efficient photon conversion and intense UVB emissions indicate that the multifunctional Gd3+-Bi3+ co-doped YBO3 orthoborate is a potential candidate for skin treatment.

J Mater Sci: Mater Electron

“…ion, the Sm 3? ion is usually incorporated into Eu 3 [17][18][19][20][21][22][23][24]. For example, the luminescent properties of activators in Ca 3 (PO 4 ) 2 :Eu 3?…”

Section: Introductionmentioning

confidence: 99%

Luminescence properties and energy transfer of a red-emitting Ca3 (PO4)2:Sm3+, Eu3+ phosphor

Wang

Chen

et al. 2015

A series of Sm 3? , Eu 3? and Sm 3? -Eu 3? doped Ca 3 (PO 4 ) 2 were prepared by a high temperature solid-state method. Their luminescent properties were studied by photoluminescence emission, excitation spectra and decay curves. Under excitation with a wavelength at 403 nm, Ca 3 (PO 4 ) 2 :Sm 3? emits red-orange light, and the dominated peak situates at 602 nm which is due to the 4 G 5/2 ? 6 H 7/2 transition of Sm 3? . Ca 3 (PO 4 ) 2 :Eu 3? produces red light under the 394 nm excitation, and the strongest peak centers at 613 nm, which is assigned to 5 D 0 ? 7 F 2 transition of Eu 3? . The energy transfer from Sm 3? to Eu 3? in Ca 3 (PO 4 ) 2 host has been studied and demonstrated to be a resonant type via a dipole-quadrupole interaction mechanism. The critical distance of Sm 3? -Eu 3? in Ca 3 (PO 4 ) 2 is calculated to be 13.5 Å . With the increase of Eu 3? doping content, the energy transfer efficiency (Sm 3? ? Eu 3? ) obtained from decay curves gradually increases to 30.7 %. Moreover, the emitting color of Ca 3 (PO 4 ) 2 :Sm 3? , Eu 3? can be tuned by appropriately adjusting the relative doping composition of Sm 3? /Eu 3? .