A novel UV-emitting phosphor: Li6CaB3O8.5:Pb2+ (original) (raw)

Synthesis and photoluminescence of LiCaBO3: M (M: Pb2+ and Bi3+) phosphor

Journal of Luminescence, 2012

Pure, Pb 2 þ and Bi 3 þ doped LiCaBO 3 materials were prepared by a solution combustion synthesis method. The phase of LiCaBO 3 were determined using the powder XRD and FTIR. The photoluminescent properties of Pb 2 þ and Bi 3 þ doped LiCaBO 3 materials were investigated using spectrofluorometer at room temperature. The emission bands of LiCaBO 3 : Pb 2 þ and LiCaBO 3 : Bi 3 þ were observed at 296 and 378 nm, respectively. LiCaBO 3 with different Pb 2 þ and Bi 3 þ doping concentrations were analyzed at room temperature. The Stokes shifts of LiCaBO 3 : Pb 2 þ and LiCaBO 3 : Bi 3 þ were calculated to be 3952 and 6440 cm À 1 , respectively.

Synthesis and PL study of UV emitting phosphor KCa4(BO3)3:Pb2+

Journal of Luminescence, 2014

Pb 2 þ doped KCa 4 (BO 3) 3 materials were prepared by a novel solution combustion synthesis technique which is slight variation of combustion synthesis method. The synthesized materials were characterized by powder XRD and FT-IR. Scanning Electron Microscopy (SEM) observation indicated that the microstructure of the phosphor consisted of irregular grains which get finer and shaped in doped sample as compared to pure. The photoluminescence properties of synthesized materials were investigated using Spectrofluorometer at room temperature. The emission and excitation bands of the synthesized phosphors were observed at 335 nm and 260 nm respectively. The concentration of Pb 2 þ for which optimum emission is obtained was found to be 0.005 mol. The critical transfer distance (R 0) for optimum concentration was determined to be 16.88 Å. The Stokes shift of KCa 4 (BO 3) 3 :Pb 2 þ was measured to be 8756 cm À 1. The phosphor could find application in medical and lamp industry.

Luminescence characteristics of LiCaAlF 6 :Eu phosphor

physica status solidi (a), 2007

A simple method for preparing LiCaAlF 6 :Eu 2+ phosphor is reported. Photoluminescence (PL) and thermoluminescence (TL) studies were carried out. The TL sensitivity of the phosphor is nearly twice that of CaSO 4 : Dy TLD phosphor. Several other properties required for TL dosimetry are superior as well. It is suggested that the phosphor can be a suitable replacement for CaSO 4 : Dy.

Combustion synthesis and preliminary luminescence studies of LiBaPO4 : Tb3+ phosphor

Bulletin of Materials Science, 2015

The polycrystalline sample of LiBaPO 4 : Tb 3+ (LBPT) was successfully synthesized by solution combustion synthesis and studied for its luminescence characteristics. The thermoluminescence (TL) glow curve of LBPT material consists of two peaks at 204.54 and 251.21 • C. The optimum concentration was 0.005 mol to obtain the higher TL intensity compared to commercial TLD-100 phosphor. The peak shape method was used to calculate kinetic parameter (activation energy and frequency factor). In CW-OSL mode its sensitivity for beta exposure was found to be 50% compared to commercially available α-Al 2 O 3 : C and 40% than LMP (BARC), and photoluminescence spectrum of LBPT shows green emission when excited with 225 nm UV source.

Novel RGB emission of Tb 3+ ion in Li 2 BaP 2 O 7 phosphor for near-UV LEDs

A red emitting Li 2 BaP 2 O 7 :Tb 3+ phosphor prepared through solid state reaction method is first time reported in this work. The main point of this work is that Tb 3+ shows intense red line in addition to blue and green lines in Li 2 BaP 2 O 7 upon UV excitation. Red line (602 nm) dominates the spectrum upon 372 nm excitation. However, the green line dominates the spectrum upon 230 nm excitation. The results are quite interesting from luminescence point of view. Therefore, we suggest a new red, green and blue emitting Li 2 BaP 2 O 7 :Tb 3+ phosphor for pc-LEDs to generate white light.

Combustion synthesis of β-Ca 1.95P 2O 7:0.05Eu 2+ blue phosphor for near ultraviolet excitation

Journal of Alloys and Compounds, 2009

Synthesis of a near ultraviolet light emitting phosphor ␤-Ca 1.95 P 2 O 7 :0.05Eu 2+ for white LEDs by combustion method is reported. The photoluminescence, powder analysis and particle morphology of the phosphors were investigated using a luminescence spectrometer (LS), X-ray diffractometry (XRD) and transmission electron microscopy (TEM). It was found that when the initiating combustion temperature reached 1000 • C, the phase of ␥-Ca(PO 3 ) 2 which begun to appear at 700 • C, transformed into the target material -the phase of ␤-Ca 2 P 2 O 7 . And the phase transition leads to a red shift of the emission peak about 9 nm. TEM images also confirm those results. The emission spectrum shows a single intense band centered at 421 nm while the excitation spectrum is a broad band extending from 250 nm to 410 nm, with two bands centered at 330 nm and 387 nm. The band at 387 nm is a main excitation peak matching the emission of near ultraviolet light (370-410 nm). The investigated phosphor is suitable for a NUV LED excitation.

Synthesis and luminescent properties of a new phosphor, La2CaB8O16:RE3+ (RE=Eu, Tb)

Journal of Alloys and Compounds, 2013

A new borate phosphor, La 2 CaB 8 O 16 :RE 3+ (RE = Eu, Tb) has been synthesized by solid-state reaction method. The local lattice environment of doping ions in La 2 CaB 8 O 16 has been determined by use of the room temperature and low temperature fluorescence spectra of Eu 3+. The luminescent properties of RE 3+-doped La 2 CaB 8 O 16 have been investigated. The dominant emission of Eu 3+ in La 2 CaB 8 O 16 is located at 616 nm corresponding to the electric dipole transition 5 D 0-7 F 2 , while the green emission of La 2 CaB 8 O 16 :Tb 3+ attributed to the transition 5 D 4-7 F 5 is centered at 544 nm. The concentration dependence of the emission intensity shows that the optimum doping concentrations of Eu 3+ and Tb 3+ are 30 mol% and 15 mol%, respectively.

Effect of co-doping on luminescence of LiCaAlF6:Eu phosphor

Journal of Luminescence, 2015

LiCaAlF 6 is a versatile host material. Applications of this host as scintillation detector and solid state laser have been reported quite frequently. Thermoluminescence studies on LiCaAlF 6 :Eu have also been reported. They are, however, not consistent. The glow curve structure depends on the synthesis route. At least two glow peaks are observed, around 180°C and 240°C. Effects of co-doping on the glow curve are reported. Co-doping with Y (0.5 mol%) suppresses the 240°C peak and increases the intensity of 180°C peak nearly 3 fold and shifts it to slightly higher temperature of 190°C. Co-doping with La (0.8 mol%), on the other hand, removes 180°C peak and intense peak at 240°C can be observed. Thus co-doping produces a relatively simple glow curve with only one dominant peak. LiCaAlF 6 :Eu phosphor also shows intense optically stimulated luminescence (OSL). The OSL sensitivity of LiCaAlF 6 :Eu codoped with Y is about 7 times that of commercially available Al 2 O 3 :C. Other OSL properties useful for dosimetry applications are also reported in this paper.

Combustion synthesis and luminescence studies of Eu (III) activated LiBaBO 3 inorganic phosphor

Optik - International Journal for Light and Electron Optics, 2016

This work offered study the rare earth doped LiBaBO3 phosphor to reveal the luminescence properties in this material. X-Ray diffraction is used to confirm the crystal structure of this material made by solution combustion synthesis route. A Photoluminescence (PL) measurement shows the phosphor exhibited intense emission at 592 nm and 615 nm respectively corresponding to 5D0→7F1 and 5D0→7F2 transitions of Eu 3+ on excitation with optimum 394 nm wavelengths. The remaining excitation peaks at 381 and 465 nm with broad band 200-310 nm are also shown in the excitation spectra. Varying the irradiation dose of gamma radiation as well as rare earth activator quantity, its thermoluminescence (TL) spectra is measured. A single TL glow peak is obtained at 170 ˚C with a shoulder around 266 ˚C for the heating rate of 5 ˚C/sec a. After deconvolution, activation energy and frequency factors are calculated for two peaks P1 and P2. The linear dose response is sketch graphically which prove this phosphor to be useful in the category of new dosimetry materials.