Luminescence Intensity Ratio Research Articles

Boltzmann thermometry: Eu3+-doped monoclinic Y2O3 and Y2O3@SiO2 nanoparticles

During last decade optical thermometry has gained considerable attention due to the possibility to determine temperature remotely in cases when traditional contact methods fail. The most widespread type of optical temperature sensors is based on monitoring luminescence intensity ratio between transition originated from thermally coupled energy levels. Eu3+ ions own the largest energy gap between thermally coupled 5D1 and 5D0 energy levels among all lanthanides, which guarantees a high thermal sensitivity of Boltzmann-type thermometry. Here, uncoated m-Y2O3:Eu3+ and core-shell m-Y2O3:Eu3+@SiO2 nanophosphors have been successfully utilized as ratiometric thermal sensors within the 298–873 K range. It was shown that the calculation method (integral or peak intensities) only slightly affects thermal sensitivity. SiO2 coating significantly enhances emission intensity and increases lifetime, but has no noticeable effect on thermal sensitivity. m-Y2O3:Eu3+ nanophosphor has the best thermometric characteristics of Sr = 0.96 % K-1 at 373K and δT = 0.5 K.

Up-Conversion Luminescence and Optical Temperature Sensing of Tb3+, Yb3+, Er3+ Doped (Gd, Y, Lu)2O2S Series Phosphors

The phase analysis, luminous intensity, and luminescence lifetime of different doping concentrations of Tb3+ (1 mol %–11 mol %), Yb3+ (9 mol %–54 mol %), Er3+ (0.1 mol %–1.1 mol %) ions and different introduction concentrations of Y3+ (1 mol %–6 mol %) and Lu3+ (0.5 mol %–3 mol %) of Gd2O2S series phosphors were studied systematically. In addition, the energy transfer model of Tb3+-Yb3+-Er3+ was established by analyzing the changes of luminous intensity and luminescence lifetime of novel (Gd, Y, Lu)2O2S phosphors co-doped Tb3+, Yb3+ and Er3+ which were prepared by the coprecipitation-high temperature solid-state reaction method. The luminescence intensity ratio equations of the sample excited by 980 nm was obtained at 313–553 K. And the absolute sensitivities were 0.0033 (313 K). This work is of reference value to the study of the mechanism of up-conversion system.

Toward Ultra-High Sensitivity Optical Thermometers and Bright Yellow LEDs Based on Phonon-Assisted Energy Transfer in Rare Earth-Doped La2ZnTiO6 Double Perovskite.

Double perovskites, a class of ceramic oxides with unique crystal structures and diverse physical properties, show promise for various technological applications including solar cells, photodetectors, and light-emitting diodes (LEDs). Despite limited research on rare earth-doped double perovskites, leveraging their ultrahigh luminous efficiency to achieve bright yellow LED emission and addressing energy transfer challenges between Yb3+ and Nd3+ ions in double perovskite La2ZnTiO6 with moderate phonon energy are explored in this work. Through phonon-assisted energy transfer, an ultrasensitive optical thermometer covering a wide temperature range is developed by utilizing the different temperature responses of Er3+ emission in the visible light region and Nd3+ emission in the near-infrared region based on the luminescence intensity ratio (LIR). All the results demonstrate that the rare earth (Yb-Er, Yb-Nd, and Yb-Nd-Er)-doped La2ZnTiO6 phosphors can be effectively utilized for ultrabright LED illumination and ultrahigh sensitivity self-calibrated temperature sensing. This research underscores the significance of phonon-assisted energy transfer in improving material properties and provides valuable insights for the advancement of multifunctional materials.

An energy transfer strategy towards versatile sensing applications from Cr3+ and Yb3+ codoped near infrared phosphors

Near-infrared (NIR) phosphors have garnered notable attention for their extensive applications in anti-counterfeiting, optical imaging, non-invasive medical diagnosis and detection. Nevertheless, the quest for NIR phosphors with outstanding detection and sensing capabilities remains a challenge. In this study, we have successfully prepared Ga1.6Mg0.2Ge0.2O3:Cr3+,Yb3+ NIR phosphors by codoping and substitutation strategies. When incorporated into polydimethylsiloxane films, these phosphors demonstrated a direct correlation between luminescence intensity ratio and applied stress under 450 nm excitation. Moreover, variations in luminescence spectra occurred with different compositions and concentrations of liquids coated on the film, facilitating both force measurement and composition analysis. Furthermore, a NIR phosphor-converted light-emitting diode (pc-LED) was fabricated by integrating phosphor with a blue LED chip, exhibiting excellent performance. Utilizing the prepared NIR pc-LED as a light source, we facilitated non-destructive imaging, night vision, and anti-counterfeiting applications with an infrared camera. These findings suggest that the synthesized NIR phosphors possess hold promise for diverse detection and sensing applications.

Heterovalent Zr4+/Nb5+‐Cosubstituted Negative Thermal Expansion Luminescent Materials with Anti‐Thermal Quenching Luminescence

AbstractRare earth luminescent materials based on negative thermal expansion (NTE) have achieved thermally enhanced photoluminescence, but these materials typically exhibit relatively weak luminescence intensity at room temperature. In this work, adopting the cationic heterovalent substitution strategy, a series of Sc2‐2xZrxNbxW3‐1.5xO12‐3x:Yb/Er (SZNWOx:Yb/Er) phosphors are prepared by solid‐state reaction. With the increase of x value, the substitution of Sc3+ by Zr4+/Nb5+ leads to a decrease in the local symmetry of Er3+. Compared with Sc2W3O12:Yb/Er (SWO:Yb/Er), this heterovalent substitution strategy significantly improves the luminescence intensity of SZNWOx:Yb/Er while retaining its anti‐thermal quenching luminescence and negative thermal expansion properties. By comparing and analyzing the temperature dependent temperature‐dependent steady‐state/transient spectra of SZNWO0.10:Yb/Er and SWO:Yb/Er phosphors, the anti‐thermal quenching mechanism is discussed from a new perspective. The luminescence intensity ratio (LIR) of the thermal coupled levels (TCL) of Er3+(2H11/2/4S3/2) is adopted for optical temperature sensing, achieving a maximum absolute sensitivity of 1.04% K−1 at 464 K and a maximum relative sensitivity of 1.08% K−1 at 298 K for the SZNWO0.10:Yb/Er phosphors. Finally, the potential applicability using the constructed flexible thin film to real‐world sensing scenarios is demonstrated, offering accurate and real‐time temperature monitoring at the local hotspot in the electronic component of the CPU chip.

Engineering Visible to Near-Infrared Luminescence through a Selective Doping Strategy for High-Performance Temperature Sensing.

Luminescence nanothermometers have garnered considerable attention due to their noncontact measurement, high spatial resolution, and rapid response. However, many nanothermometers employing single-mode measurement encounter challenges regarding their relative sensitivity. Herein, a unique class of tunable upconversion (UC) and downshifting (DS) luminescence covering the visible to near-infrared range (400-1700 nm) is reported, characterized by the superior Tm3+, Ho3+, and Er3+ emissions induced by efficient energy transfer. The outstanding negative thermal expansion characteristic of ScF3 nanocrystals has been found to guide excitation energy toward the relevant emitting states in the Yb3+-Ho3+-Tm3+-codoped system, consequently resulting in remarkable near-infrared III (NIR-III) luminescence at ∼1625 nm (Tm3+:3F4 → 3H6 transition), which in turn presents numerous opportunities for designing multimode ratiometric luminescence thermometry. Furthermore, by facilitating phonon-assisted energy transfer in Er3+-Ho3+-codoped systems, the luminescence intensity ratio (LIR) of 4I13/2 of Er3+ and 5I6 of Ho3+ in ScF3:Yb3+/Ho3+/Er3+ exhibits a strong temperature dependence, enabling NIR-II/III luminescence thermometry with superior thermal sensitivity and resolution (Sr = 0.78% K-1, δT = 0.64 K). These findings not only underscore the distinctive and ubiquitous attributes of lanthanide ion-doped nanomaterials but also hold significant implications for crafting luminescence thermometers with unparalleled sensitivity.

Construction of multifunctional core-shell structure nanoprobe integrating NIR dual-mode optical thermometer and nuclear magnetic imaging

Precise temperature regulation and imaging are critical for in vivo photothermal treatment. The goal of this work is to realize non-contact temperature measurement and imaging in biological tissues by building a multifunctional nano-platform using optical temperature probes and imaging for biological diagnosis and therapy. Here, NIR dual-mode temperature probes of NaYF4: Nd/Yb/Gd@NaNdF4 were designed according to the LIR-I of 4F3/2 → 4I9/2/2F5/2 → 2F7/2 levels in 850 – 1025 nm and LIR-II of 2F5/2 → 2F7/2/4F3/2 → 4I11/2 in 950 – 1100 nm from the emissions of Nd3+/Yb3+. Transmission electron microscope (TEM) and X-ray diffraction (XRD) data of the sample demonstrate its superior dispersibility and accurate structure. The integrated intensity ratio centered around various luminescence intensity peaks is used as a temperature sensor since luminescence intensity is temperature-dependent. Additionally, the temperature sensing capabilities of two ratio temperature sensors were examined under 808 nm laser excitation, utilizing LIR (luminescence intensity ratio) technology. Furthermore, the MRI test indicated that the sample exhibited good imaging capacity when Gd3+ was added. These results assure the auspicious application prospects of the samples in temperature sensing, photothermal therapy, and biomedical imaging.

Near‐Infrared Thermometer Based on Stark Energy Levels of Yb3+ in Garnet

A Yb3+‐doped Gd3Al2Ga3O12 garnet (GAGG) Boltzmann thermometer is prepared and studied in this work. Due to the Boltzmann distribution of the population of Stark sublevels of Yb3+, the photoluminescence peaks of Yb3+ in the wavelength range of 950–1000 and 1000–1050 nm exhibit opposite temperature dependencies, which makes the luminescence intensity ratio (LIR) of two Yb3+ peaks work as a luminescence thermometer with a relative sensitivity of 1.6% K−1 at 200 K. It is worth nothing that this LIR value still follows the Arrhenius model at temperatures as low as 200 K. In these results, it is suggested that Yb3+‐doped GAGG thermometer can achieve high sensitivity for accurate temperature measurements. In addition, the accurate position of various Stark sublevels of Yb3+ in GAGG is obtained for the first time. In this work, it is confirmed that the Yb3+‐doped GAGG thermometer exhibits potential applications in the fields of microelectronics and biology.

Luminescence and thermometry sensing of Sr2InTaO6: Eu3+, Mn4+ phosphors in a wide temperature range

Fluorescent temperature sensing materials are generally designed based on the phenomenon that the fluorescence intensity ratio (FIR) of luminescence at different wavelength positions changes linearly with temperature. Luminescence at different wavelength positions can come from two different luminescent centers. The key to the design of such materials is that the two luminescent centers have different degrees of change with temperature, that is, they have different thermal quenching behavior. Herein, we have investigated the luminescence properties and structure of Eu3+ and Mn4+ co-doped in Sr2InTaO6. The emission of doped Eu3+ (rare earth) changes little with the increase of temperature. However, the emission of doped Mn4+ (transition metal) decreases sharply with increasing temperature. Materials in two different temperature ranges (80–300 K under room temperature, and 300–523 K above the room temperature) have shown a satisfactory temperature sensing performance. This work points out a direction for the design of temperature sensing materials based on the FIR of two luminescent centers, that is, mixing an ion with excellent luminescence thermal stability (such as rare earth ion Eu3+, Sm3+, Dy3+, etc.) as a reference, and an ion with relatively poor luminescence thermal stability (such as transition metal Mn4+, main group element ion Bi3+, etc.) as the temperature scale.

Phonon-assisted upconversion luminescence thermal enhancement of NaYS2:Yb3+,Nd3+ for optical temperature sensing

Upconversion luminescence presents obvious advantages in optical temperature sensing, nevertheless the application in complex scenarios is limited by luminescence thermal quenching. Herein, NaYS2:Yb3+,Nd3+ phosphors are synthesized by the solid-gas reaction method and used for temperature sensing. A series of emissions for Nd3+ from visible to near-infrared region are achieved based on energy transfer from Yb3+ to Nd3+ under 980 nm excitation. With elevating the temperature, significant thermal enhancement effect of nearly three orders of magnitude is detected in near-infrared emission of 4F7/2 → 4I9/2, which is attributed to phonon-assisted energy transfer of Yb3+→Nd3+ and the corresponding thermal population effect. The thermal behaviors of thermally coupled energy levels for 4G7/2/2G9/2 and 4F7/2/4F5/2 in NaYS2:Yb3+,Nd3+ are evaluated by luminescence intensity ratio technique. Remarkably, the optical thermometer based on the enhanced emission of 4F7/2/4F5/2 shows excellent temperature measurement performance, which is expected to be applied in wide-temperature-range and highly-sensitive temperature sensing. These results not only provide a pathway to realize high performance temperature sensing, but also heighten the understanding of UC emission thermal enhancement.

Europium Ions Self‐Reduction Benefiting from AlO4/Si(Al)O4 Network Structure for Multimode Optical Thermometry Manometry

AbstractMixed‐valence europium ions‐activated phosphors have distinct advantages in color modulation, dynamic anti‐counterfeiting, and optical sensors. Nevertheless, it is still a challenge to obtain mixed‐valence europium ions in single compounds by facile self‐reduction. Herein, the crystal structure of a 3D hexagonal network formed by SiO4/AlO4 tetrahedra is demonstrated to play a significant role in the spontaneous reduction of Eu3+ to Eu2+ based on SrAl2Si2O8, Sr2SiO4, SrAl2O4 hosts. The crystal field theory and Judd‐Ofelt theory provide a deeper understanding of Eu2+ and Eu3+ luminescence behavior, namely, the low energy spectra of Eu2+ are more easily observed in crystal structure with high polarizability and octahedral coordination, whereas the spectra properties of Eu3+ are affected by the symmetry of local environment and crystal rigidity. For SrAl2Si2O8: 0.02Eu2+/Eu3+, multi‐mode thermometry is explored in terms of the luminescence intensity ratio (LIR) of Eu2+/Eu3+, luminescence intensity (LI) and full‐width at half maximum (FWHM) of Eu2+ with maximal relative sensitivity reaching 3.83% K−1. This study presents the first exploration of optical manometry based on the LIR mode of Eu2+/Eu3+ with excellent sensitivity (Sr = 18.13% GPa−1). This work not only provides a novel strategy for the design of mixed‐valence ions‐activated materials but also constructs promising optical thermometry, and manometry candidates.

Study on temperature-sensitive factors relevant to thermographic features of Tb3+-doped phosphate glasses

Intensities of the 5D4 luminescence with the 5D3 level populated by GSA and ESA transitions of Tb3+ in ternary phosphate glass were measured at different temperature between 300 K and 675 K. Acquired 5D4 luminescence intensities related to GSA and ESA excitation transitions from thermally coupled 7F6 and 7F5 levels were treated to assess luminescence intensity ratios (LIR) as a function of temperature and resulting values of relative sensitivity SR. To understand origin of marked dissimilarity of SR values observed in some few Tb3+-doped hosts reported thus far an in-depth analysis of the excitation energy flow in systems under study is made. Spectra of absorption cross section and temperature dependent absorption coefficient for ESA transition were evaluated. Rates of temperature dependent cross relaxation process governing energy transfer between 5D3 and 5D4 were calculated. It was supposed that temperature-dependent absorption of colour centres in the blue region may affect adversely relative thermal sensitivity.

Research on the luminescent and thermometric properties of MgMoO4: Er3+

A series of MgMoO4: x%Er3+ (x = 0, 1, 2, 3, 4, 5) phosphors were synthesized by high temperature solid-state reaction. The doping concentration of Er3+ was optimized, and the thermometric properties of the phosphors were investigated based on the thermally coupled energy levels of Er3+ (2H11/2 and 4S3/2) via the luminescence intensity ratio (LIR) technology. The absolute sensitivity (SA) and relative sensitivity (SR) of the samples were investigated with the maximum SR being 0.83%K−1. To maintain the electrical neutrality of the phosphors and reduce lattice distortion of the hosts, a certain amount of charge compensators (Li+, Na+, K+) were introduced into the phosphors. The luminescent intensity of the phosphors was enhanced greatly, and the thermometric properties were improved slightly with the maximum SR at 0.89%K−1 by the charge compensators.

Thermal Enhanced Energy Transfer and High Thermal Sensitivity of Sb3+ Doped Cs2KYbCl6 Rare Earth Double Perovskites

AbstractRare‐earth based double perovskites (DPs) have attracted much attention due to stable, efficient, and unique luminescence, and wide applications in many optoelectronic fields. However, their weak near‐infrared (NIR) emission and poor anti‐thermal quenching severely limit the further applications. Herein, Sb3+‐doped Cs2KYbCl6 DP with cyan self‐trapped exciton (STE) and NIR emission is prepared by a solvothermal method, and the separate photoluminescence quantum yields from STE and NIR emission reached ≈26.1% and 43.8%, respectively. More importantly, Sb3+ not only contributes to the absorption and energy transfer but also helps to establish an effective thermally enhanced energy transfer channel through self‐trapping state, resulting in the NIR emission with superior anti‐thermal quenching resistance. The thermal sensitivity of luminescence intensity ratio (LIR) of I1010 nm/I505 nm (I is the intensity of PL) and time‐resolved temperature sensor reach 21.4 and 13.6% K−1, respectively, which are ahead of most temperature sensing materials. Furthermore, it is found that the material exhibited advanced multifunctional applications in LED lighting, flexible luminescent thin film, and NIR imaging. This work provides in‐depth understanding on photophysical mechanisms of rare‐earth luminescent materials and references for designing high‐performance materials.

Remote optical thermometry by two-dimensional LiAl5O8:Cr3+ luminescence sensor probe

Pure-phase LiAl5O8:Cr3+ leaf-like particles were synthesized by combustion synthetic route at various concentrations. Both sharp peaks and broad emission photoluminescence are apparent even at room temperature. The most optimum doping concentration of 0.75 % based on lifetime and emission intensity was chosen. Peaks of different configurations were separated by deconvolution from 120 K to 680 K, where 4T2 peak increases in temperature to the expense of the sharp 2E emissions, giving luminescence intensity ratio (LIR) relative sensitivity of 2.8 % K−1 at room temperature. Large separation between Cr3+ R lines marks their LIR as perspective at low temperatures. At high temperatures luminescence lifetime provided for 0.8 % K−1 sensitivity, while line-shift and bandwidth methods are not sensitive enough for thermometric applications. Deconvolution of peaks enabled for 10 % more precise estimation of Debye temperature (679 K).

Dual-modal optical temperature sensing based on Sb3+/Mn2+ co-doped Cs2NaYCl6 double perovskites

Optical temperature sensing based on luminescence intensity ratio shows significant potential in achieving accurate temperature detection. In this work, Sb3+/Mn2+ co-doped Cs2NaYCl6 double perovskites were synthesised via a hydrothermal method. Introducing Sb3+ ions to the host significantly enhances the radiative recombination of self-trapped excitons (STEs), resulting in a broad blue emission. The co-doping of Mn2+ ions to the composition leads to a tunable dual-emission in the spectra, originating from the energy transfer between the STEs and Mn2+ ions. The dependence of the dual-emission on temperature is employed for optical temperature sensing. The maximum relative sensitivity, optimal thermal resolution, and optimal thermal repeatability are determined as 1.40 % K−1, 0.002 K and 99.3% at 250 K, respectively. The results indicate that the synthesised Cs2NaYCl6: Sb3+/Mn2+ double perovskites are promising candidates for high-sensitivity optical thermometers.

Thermosensitive chameleon films based on polystyrene doped with complexes of europium(III) and terbium(III)

New complexes of Eu(III) and Tb(III) tris(β-diketonates) with Lewis bases were synthesized. The spin-coating technique was used to produce composite films consisting of polystyrene (PS) polymer doped with mixtures of Eu(III) and Tb(III) complexes with different ratio of luminophores. An increase in the content of the Tb(III) complexes in the 5 %Eu x%Tb films intensifies emission of both the Tb3+ and Eu3+ ions due to occurring intermolecular energy transfer and leads to a significant increase in photostability of the material (the loss of luminescence intensity ratio did not exceed 0.5 %/hour). These photostable films were characterized as potential luminescent temperature sensors. The temperature sensitivity of their luminescence intensity and lifetime was investigated in the range of 298–383 K. The maximum absolute sensitivity of the films reaches 6.00 µs/K and exceeds that of all known lanthanide-containing thermal sensors designed for measuring physiological temperatures. In combination with changeable luminescence colors of the films, such a sensitivity makes these materials promising colorimetric thermal sensors for in situ temperature measurements.

Intense NIR-II luminescence through stabilization of tetrahedral (Mn5+O4) lumophore in apatites with high external quantum efficiency

The discovery of highly efficient near-infrared (NIR) emitting phosphors is essential for multiple spectroscopic applications. Pentavalent-manganese (Mn5+) is a rarely-reported NIR-II activator due to the its instability in inorganic solids. In this study, Mn5+-activated apatite phosphors A5(B1-xMnxO4)3X (A = Sr, Ba; B = P, V; X = OH, F, Cl, Br) were reported. Benefiting from the discrete P/VO4 tetrahedron and stabilization effect of alkaline-earth cation, Mn5+ existed as MnO43− anion can be effectively incorporated into the A5(P/VO4)3X. A selection of 16 different apatites is conducted to test the structural and compositional effect on Mn5+ stabilization and luminescence. The structure-property relationship was discussed with a detailed analysis on Mn5+ Tanabe-Sugano diagram and Dq/B calculation. Particularly, the optimized Ba5(VO4)3Cl: 0.01Mn5+ (λex = 650 nm, λem = 1181 nm) reveals an exceptional external quantum efficiency of 61.1 % with vivid turquoise body color. The multiparametric thermometry by luminescence intensity ratio (LIR) and 1E lifetime were demonstrated with excellent linear regressions (R2 > 99.9 %) and high relative sensitivities of > 1.0% K−1 in the range of physiological temperatures. A NIR-II phosphor-converted light-emitting diode (pc-LED) is fabricated with a NIR output power of 30.18 mW at 60 mA driven current and photoelectric conversion efficiency of 6.63 %.

Temperature sensing by means of a near-infrared luminescent Ca8NaBi(PO4)6F2:Nd3+ fluorapatite phosphor

Microrods of calcium sodium bismuth fluorapatite doped with neodymium, denoted as Ca8NaBi1-xNdx(PO4)6F2 (with x ranging from 0 to 0.5), were synthetized using a modified Pechini sol–gel method. The crystalline structure of these phosphors was refined using the Rietveld method and exhibited hexagonal symmetry with space group P63/m—C26h, where the lattice parameters were a = 9.3855(5) Å and c = 6.8998(6) Å for x = 0.2. The particles morphology was analyzed through SEM, revealing an average length of approximately 1.5 µm. When excited at 808 nm, the Ca8NaBi(PO4)6F2:0.2Nd3+ microrods emitted strongly at 872, 957 and 1055 nm, falling within the near-infrared region. These emissions correspond to the 4F3/2 → 4I9/2 (P2), 4F5/2 → 4I11/2(P3), 4F3/2 → 4I11/2(P1) transitions of Nd3+ ions, respectively, and are situated within the first and second biological windows. The luminescence lifetime of the 4F3/2 state of Nd3+ was measured to be 294.4 µs for the sample with the lowest Nd3+ concentration of x = 0.05. In addition, the luminescence intensity ratios P2/P1 and P3/P1 were found to be temperature dependent, potentially making it suitable for luminescent ratiometric thermal sensing. These findings suggest that the synthesized Ca8NaBi(PO4)6F2:Nd3+ microrod thermometers exhibit favorable characteristics in terms of relative sensitivity, temperature uncertainty, and repeatability within the temperature range of 303–403 K.

Spectroscopic studies of Eu doped CaF2 single crystal

The Eu-doped CaF2 crystal is investigated for potential use in visible-region solid-state lasers. The single-crystal Eu: CaF2 has an FCC crystal structure and belongs to the space group Fm-3 m, as confirmed by single-crystal X-ray diffraction. A Raman shift of 324 cm−1 has been observed in a single crystal of Eu: CaF2. The vibrational mode at low frequency is suitable for minimizing non-radiative emissions and increasing radiative emissions. Eu: CaF2 crystal has two absorption bands, at 399 nm and 415 nm, corresponding to the 7F0→5L6 and 7F0→5D3 transitions, respectively. The strongest absorption peak (399 nm) is associated with the 7F0→5L6 electronic transition. The orange-red emission was observed at 588 nm (5D0→7F1), 612 nm (5D0→7F2), 648 (5D0→7F3), and 685(5D0→7F4) when excited at 399 nm. Measurements of the luminescence intensity ratio (R) between the 5D0→7F2 (electric dipole) transition and the 5D0→7F1 (magnetic dipole) transition predict that Eu3+ ions are situated at the symmetric sites in CaF2. The radiative parameters for the Eu: CaF2 crystal are calculated using the JOES code using the Judd-Ofelt theory. The calculated total radiative transition probability (AR) is 64.54 s−1, and the radiative lifetime (τR) is 15.57 ms. Radiative transition probabilities are 43.41,7.02 and 14.10, and branching ratios are 67.26 %,10.88 % and 21.85 % for 5D0→7F1, 5D0→7F25D0→7F4 transitions respectively.