Luminescence Properties Of Pr3 Research Articles

Luminescence properties of Pr3+ doped Bi4Ge3O12 crystal fibers grown by the micro-pulling down technique

The luminescence properties of 0.5%Pr-doped BGO crystals grown by using the micro-pulling down technique were carefully investigated. Room temperature absorption spectra were registered and analyzed within the framework of the Judd-Ofelt formalism and the best fit to the data is obtained by using a modified treatment allowing for the admixture of intensity enabling wave-functions. The results indicate 3P0 and 1D2 radiative lifetimes of about 5.7 μs and 79 μs, in perfect agreement with the time-constants derived from the measured fluorescence decays at room and liquid-nitrogen temperatures. Registration of time-resolved emission and excitation spectra and calibration of the 3P0 emission spectrum in cross section unit clearly indicate that Pr-doped BGO could be the first isotropic crystalline material leading to efficient diode-pumped laser operation at room temperature with laser performances, at least in the deep-red spectral region, comparable to that found with the most important anisotropic Pr-doped fluoride and oxide crystals.

Luminescence properties of Pr3+ doped high density germanate scintillating glasses for fast-event X-ray detection

Pr 3+ doped high density germanate glasses were prepared by the melt-quenching method. The physical and luminescent properties were investigated. The glass containing BaF 2 represented maximum phonon energy of 810 cm −1 , and the glass density was greater than 6 g/cm 3 . The glass exhibited good radiation resistance under 2 h of X-ray irradiation. Intense blue, green emissions and weak red emissions were observed when the glass was excited by X-ray, and the blue fluorescence lifetimes were in the range of 9.15–12.59 μs The results show that Pr 3+ doped germanate glass could be a potential scintillating material in the field of X-ray detection for fast events.

Judd-Ofelt and luminescence properties of Pr3+ doped ZnO-Gd2O3/GdF3-BaO-P2O3 glasses for visible and NIR applications

Two optimized glasses were prepared with composition 10ZnO-10Gd2O3–10BaO–69P2O3-1Pr2O3 (1ZGPr) and 10ZnO-10GdF3-10BaO–69P2O3-1Pr2O3 (2ZGPr) by melt-quenching technique and study their structural, optical, physical and emission properties. In the absorption spectra seven absorption bands were observed corresponding to transition from 3H4 state at 443 nm (3P2), 467 nm (3P1), 481 nm (3P0), 589 nm (1D2) in visible region and 1438 nm (3F4), 1527 nm (3F3) and 1940 nm (3F2) in NIR-region. The trend observed for JO-parameters for both 1ZGPr and 2ZGPr is Ω4>Ω6>Ω2. The 2ZGPr has higher value of Ω2 parameter value than 1ZGPr, showing more covalency and asymmetric environment around Pr3+-ions. Emission in NIR region exhibits three f-f transition located at 870 nm (3P1 → 1G4), 1040 nm (1D2 → 3F3, 3F4), and 1470 nm (1D2 → 1G4). The 3P0 → 3F2 (in visible) and 1D2 → 1G4 (in NIR region) transitions has higher branching ratio and stimulated emission cross section for 2ZGPr glass than 1ZGPr glass. The Full-width-half-maxima (FWHM) is analyzed for transition at 870 nm is 61 nm for 1ZGPr and 58 nm for 2ZGPr glass. The possibility of efficient signal-amplification in E-band, S-band due to affirmative emission of Pr3+-ions within broadband wavelength region in 1ZGPr and 2ZGPr glasses with transition at 1470 nm covering E−, S– C- and L-band. The assessed values of color-coordinates (x, y) are (0.57, 0.36) and (0.54, 0.36) for 1ZGPr and 2ZGPr respectively. Hence 2ZGPr glass has enough potential enough capability to emit bright red-laser at 640 nm.

Physical, Optical and Luminescence Properties of Pr3+ Doped in Lanthanum Borate Glasses

The lanthanum borate glasses doped with Pr3+ were prepared by the melt-quenching technique for study in physical and luminescence properties. The glass composition in this study is 27.5La2O3-(72.5-x)B2O3-xPr2O3, where x = 0.0, 0.1, 0.5, 1.0, 2.0 and 3.0 mol%. The results showed that the doping of Pr2O3 with more concentration increased glass density and molar volume. Absorbed photons with 444 nm can excite the glass samples to release the strongest emission at 485 nm wavelength. The suitable concentration for adding Pr3+ into La2O3-B2O3-Pr2O3 glass, which can perform the strongest light emission, was 0.5 mol% of Pr2O3. The Judd–Ofelt (JO) Ωλ (λ = 2, 4, and 6) parameters were calculated to explore the nature of environment surrounding Pr3+ ions. The CIE chromaticity (x, y) coordinate was calculated from the emission spectra indicating its location in the yellowish and orange region. This research leads to availability for use of glass as a light source in the yellow-orange-emitting device.

Synthesis and luminescence properties of Pr3+ ion-doped Ba3 Y(PO4 )3 phosphors.

Barium yttrium phosphate (BYP) phosphor doped with trivalent praseodymium ions (BaY(1-x) (PO4 )3 :Pr3+ (x = 0, 0.01, 0.05, 0.1, 0.15, and 0.2 wt%) was synthesized using a high temperature solid-state reaction method. Structural properties were analyzed through X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. XRD patterns confirmed the structure of the synthesized phosphor and average crystalline size was estimated (approximately 63.8 Å). Vibrational functional groups were identified using FTIR spectroscopy. The emission spectrum was recorded under an 444 nm excitation wavelength, which showed various emission transitions of Pr3+ ions. Commission Internationale de l'éclairage coordinates, colour purity, and colour correlated temperature values were calculated for the BYP:Pr3+ phosphors and these coordinate values fell in the yellow region of the visible spectrum.

Synthesis, Characterization and Luminescence Properties of Pr3+, Nd3+, Eu3+ and Gd3+ Complexes with Curcumin Pyrazole

A series of new lanthanide complexes [LnCl 3 . xH 2 O:(L) 3 ] (where; L = curcumin pyrazole and Ln = Pr 3+ , Nd 3+ , Eu 3+ and Gd 3+ have been synthesized in ethanol under reflux conditions for 24 h. The synthesized complexes were characterised by elemental analysis, IR, UV-Vis, fluorescence and TGA. The formations of the nona-coordinated lanthanide complexes have been detected through elemental analysis. In IR-spectra, the formation of the new band at 460 cm -1 could convey the mode of co-ordination of nitrogen atom to the lanthanide. Absorption intensity as well as luminescence properties of the synthesised complexes were analysed through UV-Vis and fluorescence spectra to reveal the formation of complexes. The percentage weight loss of the complexes was studied with TGA analysis to check the thermal stability of the complexes. Further the quantum yields of the ligand and lanthanide complexes have been analyzed to study their comparative luminescence properties.

Origin of Pr3+ luminescence in hafnium silicate films: combined atom probe tomography and TEM investigations

Structural, chemical, and luminescence properties of Pr3+-doped HfSiOx layers fabricated by radio-frequency magnetron sputtering were examined as a function of annealing temperature. Phase separation between SiO2 and HfO2 as well as the location of Pr3+ dopants were investigated using atom probe tomography and transmission electron microscopy while optical properties of Pr3+ ions were studied using photoluminescence measurements. As a result, (i) we evidenced the location of the Pr3+ dopants in the HfO2 phase while the SiO2 phase was discovered to be free of these dopants, (ii) the HfO2 phase was identified to crystallize in the cubic phase until 1050 °C annealing, (iii) no Pr clusters were detected as function of annealing, and (iv) luminescence properties were discussed in regard to the location of Pr in the HfO2 cubic phase.

Luminescence and Energy Transfer between Ce3+ and Pr3+ in BaY2Si3O10 under VUV-vis and X-ray Excitation.

A detailed investigation on photoluminescence properties and energy transfer (ET) dynamics of Ce3+, Pr3+-doped BaY2Si3O10 is provided along with the potential X-ray excited luminescence application. The luminescence properties of Pr3+ are studied in VUV-UV-vis spectral range at low temperature, and the spectral profiles of Pr3+3P0 and 1D2 emission lines are determined using time-resolved emission spectra. Upon 230 nm excitation, the electron population from Pr3+ 4f5d state to its 4f2 excited state is discussed in detail. As Pr3+ concentration rises, Pr3+3P0 and 1D2 luminescence possess different concentration-related properties. The incorporation of Ce3+ in the codoped sample produces the strong Ce3+ luminescence under 230 nm excitation, which is the combined result of Pr3+ 4f5d → Ce3+ 5d ET and Ce3+ intrinsic excitation. On the other hand, the increasingly strong ET of Ce3+ 5d → Pr3+ 4f2 results in the decrease of Ce3+ emission intensity and the gradual deviation of Ce3+ luminescence decay from the single exponential in the system. By employing the Inokuti-Hirayama model, the dipole-dipole interaction is confirmed as the predominant multipolar effect in controlling this ET process, and the value of C DA is determined to be 9.97 × 10-47 m6·s-1. Finally, the relatively low scintillation light yield of Ce3+-doped BaY2Si3O10 material impedes its application potential in the scintillator field, and the cosubstitution of Pr3+ results in the observable decline of scintillation performance.

Synthesis and Luminescence Properties of Pr3+-Doped BiPO4 Polycrystals

Synthesis and Luminescence Properties of Pr³⁺-Doped BiPO₄ Polycrystals

Synthesis and Luminescence Properties of Pr³⁺-Doped BiPO₄ Polycrystals

Synthesis and Luminescence Properties of Pr³⁺-Doped BiPO₄ Polycrystals

Luminescence properties of Pr3+ doped (Y0.9La0.1)2O3 transparent ceramics for potential applications in white LEDs and scintillators

(PrxY0.9La0.1)2O3 (x = 0.05, 1, 5) transparent ceramics were fabricated by conventional ceramic processing. The absorption, emission spectra excited by ultraviolet and X-ray as well as the excitation spectra have been investigated as a function of the Pr3+ concentration. The emission under ultraviolet excitation shows the ability of Pr3+ to downconvert ultraviolet light to blue emission. The strong excitation band at 430–520nm is in good agreement with the emissions of InGaN blue chips (λem = 450–470nm), which can be efficiently excited by the 470nm light and generate bright red emission at around 630nm. The radioluminescence spectra demonstrate the possible application of Pr3+: (Y0.9La0.1)2O3 in scintillator. In addition, the concentration quenching observed in the case of the P1 and P5 ceramics leads us to conclude that an optimum Pr3+ concentration to generate the best luminescence properties is achievable. Given overall luminescence properties, the low Pr3+ content (0.5mol%) doped (Y0.9La0.1)2O3 transparent ceramic is a potential candidate for the applications in the ultraviolet-based and InGaN blue chip based white light-emitting diodes, as well as the scintillators.

Luminescence properties of Pr3+ and Bi3+ co-doped NaCaTiNbO6 phosphor for red-LEDs

This paper investigates the photoluminescence properties of NaCaTiNbO6:Pr3+ and NaCaTiNbO6:Pr3+, Bi3+ phosphors. NaCaTiNbO6:Pr3+ and NaCaTiNbO6:Pr3+,Bi3+ powder were synthesized successfully by solid state reaction method. Phase purity was checked using X-ray powder diffractometry (XRD). The excitation and emission spectra were recorded to elucidate the photoluminescence properties of NaCaTiNbO6:Pr3+ and NaCaTiNbO6:Pr3+,Bi3+. Furthermore, fluorescence lifetime measurements were performed. The excitation spectra of NaCaTiNbO6:Pr3+ show a main band centered at around 357 nm. The luminescence spectra of NaCaTiNbO6:Pr3+ exhibit a red emission peak at 615 nm from the 1D2 → 3H4 transition of Pr3+ ions. With the introduction of the Bi3+ ion into NaCaTiNbO6:Pr3+, the luminescence intensity is enhanced nearly two times. Meanwhile, the absorption band edge of NaCaTiNbO6:Pr3+ is shifted from 380 to 420 nm. Thus, this study shows that the red phosphor NaCaTiNbO6:Pr3+ incorporated with Bi3+ is advantageous for light-emitting diode applications.

Spectral analysis of Pr3+ doped germanate glasses modified by BaO and BaF2

Luminescence properties of Pr3+ ions in germanate glasses modified by BaF2 were investigated. Several luminescence bands originating to transitions from the 3P0 state to the lower-lying states of Pr3+ were registered under 450nm excitation. The spectral analysis suggests that the positions of luminescence bands and their relative intensities are changed significantly with BaF2 content. The relative integrated luminescence intensities of 3P0→3H4 transition (blue) to the 3P0→3F2 transition (red) of Pr3+ ions strongly depend on fluoride modifier BaF2 in glass composition. The luminescence bands of Pr3+ ions are shifted to shorter wavelengths with increasing BaF2 content.

Luminescence properties of Pr3+ doped Li2O–MO–B2O3 glasses

Lithium borate glasses of composition 30Li2O–10MO–59B2O3:1Pr2O3 (MO=ZnO, CaO and CdO) were prepared by a conventional melt quenching method. The amorphous nature of these glasses was confirmed by X-ray diffraction. Characterization of these glasses was carried out by differential scanning calorimetry and infrared spectra. Optical absorption and photoluminescence spectra of these glasses were investigated. Judd–Ofelt intensity parameters Ωλ (λ=2, 4, and 6) are evaluated from the intensities of various absorption bands of optical absorption spectra. From this theory various radiative properties like transition probability A, branching ratio βr, the radiative lifetime τR, and the stimulated emission cross-section σP for various emission levels of these glasses have been determined and reported. The relationship between the structural modifications and luminescence efficiencies of all the three glasses is explained. After X-ray irradiation on these glasses, the thermoluminescence emission properties were also studied. The thermoluminescence studies indicate that CdO modified glass gives out the maximum thermoluminescence light output among the three glasses studied.

Synthesis and luminescence characterization of Pr3+ doped Sr1.5Ca0.5SiO4 phosphor

Luminescence properties of Pr3+ activated Sr1.5Ca0.5SiO4 phosphors synthesized by solid state reaction method are reported in this work. Blue, orange red and red emissions were observed in the Pr3+ doped sample under 444nm excitation and these emissions are assigned as 3P0→3H4, 3P0→3H6 and 3P0→3F4 transitions. The emission intensity shows a maximum corresponding to the 0.5wt% Pr3+ ion. The decay analysis was done for 0.05 and 0.5wt% Pr3+ doped samples for the transition 3P0→3H6. The life times of 0.05 and 0.5wt% Pr3+ doped samples were calculated by fitting to exponential and non-exponential curve respectively, and are found to be 156 and 105μs respectively. The non-exponential behaviour arises due to the statistical distribution of the distances between the ground state Pr3+ ions and excited state Pr3+ ions, which cause the inhomogeneous energy transfer rate. The XRD spectrum confirmed the triclinic phase of the prepared phosphors. The compositions of the samples were determined by the energy dispersive X-ray spectra. From the SEM images it is observed that the particles are agglomerated and are irregularly shaped. IR absorption bands were assigned to different vibrational modes. The well resolved peaks shown in the absorption spectra are identical to the excitation spectra of the phosphor samples. Pr3+ activated Sr1.5Ca0.5SiO4 phosphors can be efficiently excited with 444nm irradiation and emit multicolour visible emissions. From the CIE diagram it can be seen that the prepared phosphor samples give yellowish-green emission.

Luminescent properties and quenching effects of Pr3+ co-doping in SiO2:Tb3+/Eu3+ nanophosphors

Luminescence properties of Pr3+ single doped SiO2 and Pr3+ co-doped SiO2:Tb3+/Eu3+ nanophosphors synthesized using sol–gel method were investigated. X-ray diffraction (XRD), and scanning electron microscope (SEM) were used to study the phase structure and particle morphology, respectively. The photoluminescence (PL) and cathodoluminescence (CL) properties of SiO2:Pr3+ and Pr3+ co-doped SiO2:Tb3+/Eu3+ were investigated. The concentration quenching effects at high concentrations of Pr3+ were observed from both PL and CL data. The PL and CL intensities from SiO2:Eu3+/Tb3+ nanophosphors were shown to decrease significantly with Pr3+ co-doping and the possible causes for the decrease are discussed Fluorescence lifetimes of the 1D2 emitting level of Pr3+ were determined from luminescence decay curves of SiO2:Pr3+ at different Pr3+ concentrations.

The luminescence properties of rare-earth ions in natural fluorite

For the first time, the luminescence properties of Pr3+, Nd3+ and Tm3+ and Yb3+ ions in fluorite crystal have been obtained by steady-state measurements. In addition, the luminescence spectra of Ce3+, Sm2+, Sm3+, Dy3+, Er3+ and Yb3+ were measured. It was pointed out that λexc. = 415 nm is most suitable for measuring the Ho3+ emission beside the Er3+. The emission of trivalent holmium and erbium ions was measured independently using time-resolved measurements and tentative assignment of luminescence lines to C 3v and C 4v symmetry sites was proposed. Besides for natural fluorite crystal, the transitions between Stark energy levels of lanthanide ions were presented.

Synthesis and Tunable Luminescent Properties of Red PhosphorLi1−mAgmLa0.99−nYnPr0.01(MoO4)2with Blue Excitation for WhiteLEDs

Preparation ofLi1−mAgmLa0.99−nYnPr0.01(MoO4)2phosphors was done by a convenient method of solid‐state reaction technique in the air. The effects of synthesis temperature, substitution ofAg+,Y3+on theLiLa(MoO4)2crystal structure, and luminescence properties ofPr3+in the molybdate host are investigated systematically. The observed excitation and emission spectra indicate that the phosphor can be excited effectively by the blue light (440–500 nm) and exhibit a satisfactory red emission at 605 and 649 nm, respectively. The substitution of a littleAg+forLi+enhances thePr3+luminescence intensity drastically. The variability ofY3+andLa3+content changes the emission intensity ratio of the1D2 → 3H4and3P0 → 3F2transition, so that theCIEchromaticity coordinates of the as‐preparedLi1−mAgmLa0.99−nYnPr0.01(MoO4)2phosphors are tuned from (0.639, 0.351) to (0.653, 0.337).

Growth and luminescence properties of Pr3+-doped single crystalline films of garnets and perovskites

Abstract Peculiarities of growth of single crystalline films (SCF) of Pr 3+ doped Y 3 Al 5 O 12 and Lu 3 Al 5 O 12 garnets and YAlO 3 and LuAlO 3 perovskites by the liquid phase epitaxy method from melt-solutions based on PbO–B 2 O 3 flux as well as luminescent and scintillation properties of these SCFs were studied in this work. Dependence the intensity of the Pr 3+ d-f and f-f-luminescence on the activator concentration and influence of Pb 2+ flux dopant on the light yield of SCFs of the mentioned garnets and perovskites were analyzed.

Synthesis and luminescence properties of Pr3+ doped Ca x Ba1−x TiO3 (0.3⩽x

Ca x Ba1−x TiO3 (CBT) fine particles doped with red luminescence center of Pr3+ ions (Pr: CBT) were successfully synthesized by salt assisted spray pyrolysis (SASP) process. Scanning electronic microscope (SEM) and laser scattering analysis demonstrate that salt can be removed from the surface of particles by washing with Milli-Q water and the particles can be further separated by ball-milling to get well-dispersed Pr3+ ions doped CBT fine particles. The luminescence properties, such as photoluminescence (PL) and mechanoluminescence (ML), of as-synthesized Pr: CBT particles were investigated. For Pr: CBT fine particles with different Ca molar ratios, all the samples show one emission at 612 nm, with increasing Ca molar ratio, PL intensity of Pr: CBT fine particles become stronger and stronger. When pressure was loaded on the Pr: CBT pellet, mechanoluminescence(ML) emission was measured. The results show that the ML intensity is proportional to the applied pressure.