Luminescent properties and energy transfer mechanism of NaGd(MoO4)2:Sm3+, Eu3+ phosphors

Sm³⁺ singly doped NaGd(MoO₄)₂ and Sm³⁺, Eu³⁺ co-doped NaGd(MoO₄)₂ phosphors by using sodium citrate as chelating agent were synthesized via hydrothermal method. The structure and morphology were characterized by means of X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). During the synthesis process, the Na₃Cit concentration plays a crucial role in determining the morphology and particle size of the products. The optimal doping concentration in Sm³⁺ singly doped NaGd(MoO₄)₂ phosphor was confirmed. The relevant parameters of energy transfer in the NaGd(MoO₄)₂: Sm³⁺, Eu³⁺ phosphors have been calculated based on the fluorescent dynamic analysis. Finally, on the analysis of luminescent spectra and fluorescent dynamics, the main energy transfer mechanism between Sm³⁺ and Eu³⁺ in NaGd(MoO₄)₂ phosphor is confirmed to be electric dipole-dipole interaction, and energy transfer pathway is from ⁴G_5/2 state of Sm³⁺ to ⁵D₀ state of Eu³⁺ rather than ⁵D₁ of Eu³⁺ ions.     

Enhancing upconversion emission and temperature sensing modulation of the La2(MoO4)3: Er3+, Yb3+ phosphor by adding alkali metal ions

Trivalent Er³⁺-doped La₂(MoO₄)₃ upconversion phosphors with intense green emmision were synthesized at 800 °C by the solid-state reaction route, promoting the development of novel optical thermometry. The color emitted from the samples was minorly affected by the excitation power and doping concentration. Yb³⁺ is a better sensitizer for the La₂(MoO₄)₃: Er³⁺ phosphor and it can enhance the emission intensity when a certain amount is co-doping in the system. The up-conversion luminescent mechanism was investigated using the pump power-dependent UC emission spectra. Alkali metal doping increased the up-conversion emission intensities drastically, and Li⁺ ions can enhance the luminous intensity by more than 20 times. The fluorescence intensity ratio of the transition emission ²H_11/2-⁴I_15/2 and ⁴S_3/2-⁴I_15/2 was used to study upconversion optical temperature sensing. The sensitivity changes from doping with diverse alkali metal ions and their effects on the optimal temperature range are discussed in detail. Alkali metal ions doping extended the temperature range, indicating that this phosphor is a potential candidate for temperature-sensing probes.     

Charge transfer band excitation of La3NbO7:Sm3+ phosphors induced abnormal thermal quenching toward high-sensitivity thermometers

Different luminescent behaviors of La₃NbO₇:Sm³⁺ phosphors under the excitations of charge transfer band (CTB, 250 nm) and featured absorption peak (⁶H_5/2 → ⁴H_7/2, 405 nm) of Sm³⁺ ions were demonstrated. Under the excitation wavelength of 405 nm, the optimal La₃NbO₇:0.1Sm³⁺ phosphor exhibited an orange-red emission while the chromatic coordinate was found to be (0.609, 0.387), which also showed the excellent thermal performance, exhibiting its emission intensity of about 90.67% at 423 K with respect to 303 K. In the case of CTB excitation, the La₃NbO₇:0.1Sm³⁺ phosphor emitted an orange-yellow region with the chromaticity coordinate of (0.540, 0.443), and the emission intensity was stronger than the above one (λ_ex =405 nm) even though the optimized sample would be changed to the La₃NbO₇:0.05Sm³⁺ phosphor. With the increase of temperature, the obtained sample revealed an abnormal thermal quenching phenomenon between the emission peak of the host material and the emission transition of ⁴G_5/2 → ⁶H_9/2 under the excitation wavelength of 250 nm, which could be suggested to turn into a pair of thermal-couple levels. Therefore, the sensing sensitivity of the obtained sample was further investigated based on the fluorescence intensity ratio theory. Eventually, the absolute and relative sensing sensitivities of the La₃NbO₇:0.01Sm³⁺ phosphor were estimated to be as high as 5.379 × 10⁻² K⁻¹ and 1.60% K⁻¹, respectively.     

Improved photoluminescence and multi-mode optical thermometry of Er3+/Yb3+ co-doped (Ba,Sr)3Lu4O9 phosphors

Contactless optical thermometers have attracted extensive attentions for applications in scientific research and technological fields due to their apparent advantages. Herein, a novel sequence of Ba_3-xSr_xLu₄O₉ (B_3-xS_xLO):Er³⁺/Yb³⁺ phosphors were successfully prepared to investigate the temperature sensing property. By establishing energy transfer from Yb³⁺ to Er³⁺ and regulating the local lattice environment, up-conversion luminescence of Er³⁺ is dramatically improved when excited by 980 nm laser. This can effectively promote signal-noise ratio and reduce the errors in temperature detection. Furthermore, a multi-mode optical thermometry, which includes the fluorescence intensity ratio (FIR) from two thermally coupled levels of ²H_11/2/⁴S_3/2, FIR based on non-thermally coupled system of ²H_11/2/⁴F_9/2 and fluorescence lifetime of ⁴S_3/2 state of Er³⁺, was explored systematically. The fabricated samples exhibit the superior temperature measurement performances containing wide temperature-sensing range, superior signal discriminability, high sensitivity and favorable repeatability, indicative of the enormous utilization prospects of B_3-xS_xLO:Er³⁺/Yb³⁺ for thermometry.     

Synthesis and photoluminescence properties of CaGd2(MoO4)4:Eu3+ red phosphors

The novel red-emitting Eu³⁺ ions activated CaGd₂(MoO₄)₄ phosphors were prepared by a citrate sol–gel method. The X-ray diffraction patterns confirmed their tetragonal structure when the samples were annealed above 600 °C. The photoluminescence excitation spectra of CaGd₂(MoO₄)₄:Eu³⁺ phosphors exhibited the charge transfer band (CTB) and intense f–f transitions of Eu³⁺ ion. The optimized annealing temperature and Eu³⁺ ion concentration were analyzed for CaGd₂(MoO₄)₄:Eu³⁺ phosphors based on the dominant red (⁵D₀→⁷F₂) emission intensity under NUV (394 nm) excitation. All decay curves were well fitted by the single exponential function. These luminescent powders are expected to find potential applications such as WLEDs and optical display systems.     

Energy transfer and multicolor tunable emission in single-phase Tb3+, Eu3+ co-doped Sr3La(PO4)3 phosphors

A series of green-to-red color-tunable Sr₃La(PO₄)₃:Tb³⁺, Eu³⁺ phosphors were prepared by high temperature solid-state method. The crystal structures, photoluminescence properties, fluorescence lifetimes, and energy transfer of Sr₃La(PO₄)₃:Tb³⁺, Eu³⁺ were systematically investigated in detail. The obtained phosphors show both a green emission from Tb³⁺ and a red emission from Eu³⁺ with considerable intensity under ultraviolet (UV) excitation (~377 nm). The emission colors of the phosphors can be tuned from green (0.304, 0.589) through yellow (0.401, 0.505) and eventually to red (0.557, 0.392) due to efficient Tb³⁺-Eu³⁺ energy transfer (ET). The Tb³⁺→Eu³⁺ energy transfer process was demonstrated to be quadrupole-quadrupole mechanism by Inokuti-Hirayama model, with maximum ET efficiency of 86.3%. The results indicate that the Sr₃La(PO₄)₃:Tb³⁺, Eu³⁺ phosphors might find potential applications in the field of lighting and displays.     

Dual-mode optical thermometry based on intervalence charge transfer excitations in Tb3+/Pr3+ co-doped CaNb2O6 phosphors

Self-calibrated temperature measurements combined with luminescence intensity ratio (LIR) and luminescence lifetime are more accurate. A dual-mode self-calibration optical thermometer was designed based on CaNb₂O₆: Tb³⁺/Pr³⁺ phosphor. The obtained sample has excellent sensitivity, with the maximum values of absolute sensitivity (S_a) and relative sensitivity (S_r) being 0.69 K^-1 at 612 K and 2.50% K^-1 at 532 K for LIR mode, and 0.0059 K^-1 at 475 K and 2.62% K^-1 at 535 K for luminescence lifetime mode, respectively. These results indicate that CaNb₂O₆: Tb³⁺/Pr³⁺ phosphor has valuable potential application for self-calibration optical temperature measurement.     

Na2GdMg2V3O12:Sm3+ phosphors for three-mode optical temperature sensing

Multi-mode optical thermometry is emerging as a promising technique for accurate temperature measurement. Here, a series of Na₂GdMg₂V₃O₁₂:Sm³⁺ (NGMVO:xSm³⁺) phosphors with dual-emission centers were successfully elaborated. Irradiated by 349 nm light, NGMVO:Sm³⁺ can generate emissions from VO₄³⁻ and Sm³⁺ simultaneously due to energy transfer between them. Benefitting from difference of thermal quenching performance of two luminescent centers, fluorescence intensity (FI), fluorescence intensity ratio (FIR), and Commission Internationale de L'Eclairage coordinate modes of NGMVO:Sm³⁺ thermometer were designed. Maximum relative sensitivities (S_R) are found to be as high as 2.21 %K⁻¹, 2.12 %K⁻¹, and 0.244 %K⁻¹, respectively. Besides, with temperature increasing, S_R values of FI and FIR modes decrease slowly. Their minimal S_R values between 303 and 513 K maintain above 1.36 %K⁻¹ and 1.08 %K⁻¹, respectively. Our findings reveal that NGMVO:Sm³⁺ phosphors have promising applications for multimode temperature senor.     

Morphology control and temperature sensing properties of micro-rods NaLa(WO4)2:Yb3+,Er3+ phosphors

Uniform spindle-like micro-rods NaLa(WO₄)₂:Yb³⁺,Er³⁺ phosphors are prepared by the solvothermal method in the text. Controllable morphology of NaLa(WO₄)₂ crystal can be obtained by adjusting the prepared temperature, PH value, complexing agent content, and solvent ratio. Uniform NaLa(WO₄)₂:Yb³⁺,Er³⁺ micro-rods of 1.8 μm in length and 0.5 μm in width are synthesized at a low temperature of 120°C. The prepared NaLa(WO₄)₂:Yb³⁺,Er³⁺ phosphors present green upconversion luminescence under 980 nm excitation, luminescence intensity reaches to maximum at the Yb³⁺ and Er³⁺ concentration of 6 and 2 mol%. The temperature performance of the NaLa(WO₄)₂:Yb³⁺,Er³⁺ phosphors are evaluated based on thermal coupling technology. Temperature dependence of the two green emissions ratio of Er³⁺ ion is obtained, and the sensitivity of the sample can be calculated, the maximum sensitivity of NaLa(WO₄)₂:Yb³⁺,Er³⁺ is up to 0.019 K⁻¹ at the sample temperature of 564 K.     

Up-conversion luminescence and temperature-sensing properties of Li+, K+ doped Na2Zn3Si2O8: Er3+ phosphors

In this work we detail the preparation of new luminescent Li⁺ and K⁺ doped Na₂Zn₃Si₂O₈: Er³⁺ up-conversion phosphors using the high-temperature solid-phase method. We investigate the phosphors phase structure, elemental distribution, up-conversion luminescence characteristics and temperature sensing properties. Our fabricated samples were found to be homogeneous and when excited using 980 nm light, they emitted wavelengths in the green and red visible wavelength bands, which correspond to two major emission bands of Er³⁺. Doping with Li⁺ and K⁺ increased the luminescence intensity of the Na₂Zn₃Si₂O₈: Er³⁺ phosphor at 661 nm by 36 and 21 times respectively. The highest relative temperature sensitivity (Sa) of the fabricated phosphor reached a value of 19.69% K^?1 and the highest absolute temperature sensitivity (Sr) reached 1.20% K^?1. These values are superior to other materials which utilize up-conversion by Er³⁺ ions as a tool for temperature sensing. We anticipate that these new phosphors will find significant application as components in optical temperature measurement systems.     

EDTA-assisted hydrothermal synthesis of KLa(MoO4)2:Eu3+ microcrystals and their luminescence properties

Monoclinic KLa(MoO₄)₂:Eu³⁺ microarchitectures with different morphologies were synthesized by an EDTA-assisted hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR) and photoluminescence (PL) spectrometer. It was found that the amounts of EDTA and the pH values of precursor solution have crucial influences on the structure, morphology and size of the obtained samples, respectively. Under 270 nm excitation, Eu³⁺ doped KLa(MoO₄)₂ samples showed red emission centered at 618 nm which attributed to ⁵D₀→⁷F₂ transition of Eu³⁺. The dependence of luminescence intensity on different morphologies were discussed in detailed. With further annealing treatment, the emission intensities of peanut-like samples increased amazingly. Moreover, the lifetime of the annealed samples were calculated. The significantly enhanced photoluminescence performances indicate that the as-annealed samples are promising phosphors which can be used for white light-emitting diodes (WLEDs).     

Tunable single-phase white-light-emitting Ba2Mg(BO3)2:Ce3+, Na+, Tb3+, Eu2+ phosphor based on energy transfer

A series of white-light-emitting phosphors of single-phase Ba₂Mg(BO₃)₂:Ce³⁺, Na⁺, Tb³⁺, Eu²⁺ were synthesized by conventional solid-state reaction. The crystal structure of the host was characterized by X-ray diffraction and investigated by Rietveld refinement. Photoluminescence properties were studied in detail. The energy transfer from Ce³⁺ to Tb³⁺ in Ba₂Mg(BO₃)₂ host was investigated and demonstrated to be a resonant type via a quadrupole–quadrupole mechanism. White light with wavelength tunable was realized by coupling the emission bands peaking at 417, 543 and 626 nm attributed to Ce³⁺, Tb³⁺ and Eu²⁺, respectively. By properly tuning the relative composition of Ce³⁺(Na⁺)/Tb³⁺/Eu²⁺, optimized Commission Internationale de l׳Eclairage (CIE) chromaticity coordinates (0.363, 0.295), high color rendering index (CRI) 90 and low correlated color temperature (CCT) 3793 K were obtained from the phosphor of Ba_1.90Ce_0.04Na_0.04Eu_0.02Mg_0.94Tb_0.06(BO₃)₂ upon the excitation of 296 nm UV radiation. These results indicate that Ba₂Mg(BO₃)₂:Ce³⁺, Na⁺, Tb³⁺, Eu²⁺ phosphor has a potential application as an UV radiation down-converting phosphor in white-light-emitting diodes.     

Dual-activator luminescence of LuAG:Mn4+/Tb3+ phosphor for optical thermometry

Mn⁴⁺ and Tb³⁺ singly doped and Mn⁴⁺/Tb³⁺ codoped lutetium aluminum garnet (Lu₃Al₅O₁₂, or simply LuAG) phosphors were synthesized and investigated for the application of optical thermometry. X-ray powder diffraction and luminescence spectroscopy measurements were performed on all samples to analyze their crystal phases and optical properties. In particular, temperature-dependent luminescence of the LuAG:Mn⁴⁺/Tb³⁺ sample was measured at the temperature range of 270–420 K. The results showed that the luminescence intensity of Mn⁴⁺ has gone through a remarkable decline while the luminescence of Tb³⁺ has an only insignificant change with the rise of temperature which leads to a dramatic decrease in the fluorescence intensity ratio (FIR) between the two activator Mn⁴⁺ and Tb³⁺. Further analysis showed that the LuAG:Mn⁴⁺/Tb³⁺ sample used for temperature sensing has a high relative sensitivity with maximum value of 4.3% K⁻¹ at 333 K. Our research indicated that this LuAG:Mn⁴⁺/Tb³⁺ material is a promising candidate for FIR-type optical temperature sensing.     

Luminescence characteristics of SrZnSO:M (M = Bi3+, Mn2+ and Tb3+) phosphors

Bi³⁺/Tb³⁺/Mn²⁺-activated SrZnSO phosphors were prepared to investigate their luminescence characteristics. The SrZnSO:Bi³⁺, SrZnSO:Mn²⁺ and SrZnSO:Tb³⁺ phosphors, excited by the NUV/blue light, show blue, orange and green emissions, respectively. The Bi³⁺ → Tb³⁺, Tb³⁺ → Mn²⁺ and Bi³⁺ → Mn²⁺ energy transfer processes take place in Bi³⁺/Tb³⁺-, Tb³⁺/Mn²⁺-, Bi³⁺/Mn²⁺- and Bi³⁺/Tb³⁺/Mn²⁺-activated SrZnSO phosphors, which result in tunable luminescence of these phosphors. The CIE coordinates were calculated on the basis of the emission spectra, and they reflect the emission color changes of phosphors. For the Bi³⁺/Tb³⁺-, Tb³⁺/Mn²⁺- and Bi³⁺/Mn²⁺- activated SrZnSO phosphors, the emission points are located in the cyan, yellow and white light regions, respectively. For the Bi³⁺/Tb³⁺/Mn²⁺-activated SrZnSO phosphors, the light is in warm white light region.     

Luminescence and optical thermometry based on silico-carnotite Ca3Y2Si3O12: Pr3+ phosphor

The photoluminescence and temperature sensitivities of Ca₃Y₂Si₃O₁₂:Pr³⁺ thermo-phosphors with silico-carnotite structure obtained by solid state reaction method were investigated. Pr³⁺ ions were accommodated in the A sites having coordination number of 9 in AB₂C₂(SiO₄)₃ to replace Y³⁺ ions. The typical sample consisted of microcrystals with an irregular structure and the surface of particles was smooth, which could enhance the luminescence due to reducing the scattering and non-radiation produced by rough surfaces. The band gap value of typical sample was about 4.01 eV. Dipole-dipole interaction could account for concentration quenching. The two thermometry strategies including normalized intensities from ³P₀→³H₄ transition and Fluorescence intensity ration (FIR) of ³P₀→³H₄/³P₁→³H₅ transitions were employed for temperature sensing in 298–573 K. The results revealed that Ca₃Y₂Si₃O₁₂:Pr³⁺ thermo-phosphors had good temperature sensitivity performance with maximum S_r of 0.59% K^?1@573 K and 0.762% K^?1@298 K in the above two methods, respectively. Hence, Ca₃Y₂Si₃O₁₂:Pr³⁺ would be a promising candidate in the field of optical thermometry.     

Temperature dependent upconversion properties of Yb3+:Ho3+ co-doped Gd2O3 nanoparticles prepared by pulsed laser ablation in water

Yb³⁺:Ho³⁺ co-doped Gd₂O₃ nanoparticles were successfully synthesized by pulsed laser ablation in water under different laser energy. The phase structure, morphology, crystallization and upconversion photoluminescence properties of obtained samples were investigated using X-Ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and photoluminescence spectra. The mechanism of the upconversion process was discussed based on the energy level diagram and power dependent upconversion emission. Upconversion mechanisms and thermal effects caused by absorption of excitation laser were discussed. Temperature dependent green and red emissions of Yb³⁺:Ho³⁺ co-doped Gd₂O₃ nanoparticles under the excitation of 980 nm were investigated in the low temperature range of 130 K–280 K. Non-radiative decay rate theory was used to explain the difference of quenching rates of green and red emissions. A further study on temperature sensing properties based on fluorescence intensity ratio (FIR) of green and red emissions was carried out. The FIR as a function of temperature can be well fitted by the model based on the thermal quenching theory. The relative sensitivity reaches its maximum value of 0.804% K⁻¹ at 216 K.     

Luminescence and optical thermometry strategy based on emission and excitation spectra of Pr3+ doped SrMoO4 phosphors

Recent developments of luminescence ratiometric thermometry have attracted much attention owing to its merits of fast response, non-invasiveness and high spatial resolution. In this work, the synthesis, crystal structure and luminescence properties has been carried out for Pr³⁺-activated SrMoO₄ phosphors as optical thermometry. The XRD results show that all the phosphors possess the scheelite type tetragonal structure with space group I4₁/a. The efficient luminescence of Pr³⁺ can be observed under intra-configurational (4f-4f) and charge transfer band (Mo–O) excitations, respectively. Upon different excitations, the quenching concentration of Pr³⁺ is diverse due to the multi-phonon relaxation and cross-relaxation processes occurring in different excited states of Pr³⁺ ions. The fluorescence intensity ratio (FIR) techniques based on emissions of ³P₀ and ¹D₂ excited states of Pr³⁺, and the FIR in the excitations of the charge transfer band (Mo–O) and 4f-4f transitions of Pr³⁺ were employed for the thermometric characterizations in the 298–498 K range. Both results show remarkable performance in temperature sensing with the maximum relative sensitivity of 0.45%K^?1@489 K and 0.98 %K^?1@298 K, respectively. Our study demonstrates that Pr³⁺-activated SrMoO₄ phosphors have a promising potential application in non-contact optical thermometry.     

Preparation,luminescence properties and energy transfer of Ca9Y(PO4)7: Eu2+‐Tb3+ phosphors

Tb³⁺‐doped and Eu²⁺, Tb³⁺ co‐doped Ca₉Y(PO₄)₇ phosphors were synthesized by conventional solid‐state method. Additionally, the luminescence properties, decay behavior and energy transfer mechanism have already been investigated in detail. The green emission intensity of Tb³⁺ ions under NUV excitation is weak due to its spin‐forbidden f‐f transition. While Eu²⁺ can efficiently absorb NUV light and yield broad blue emission, most of which can be absorbed by Tb³⁺ ions. Thus, the emission color can be easily tuned from cyan to green through the energy transfer of Eu²⁺→Tb³⁺ in Ca₉Y(PO₄)₇:Eu²⁺,Tb³⁺ phosphor. In this work, the phenomenon of cross‐relaxation between ⁵D₃ and ⁵D₄ are also mentioned. The energy transfer is confirmed to be resulted from a quadrupole‐quadrupole mechanism.     

Photoluminescence and energy transfer of efficient and thermally stable white-emitting Ca9La(PO4)7:Ce3+, Tb3+, Mn2+ phosphors

The development of novel single-component white-emitting phosphors with high thermal stability is essential for improving the illumination quality of white light-emitting diodes. In this work, we synthesized a series of Ce³⁺, Tb³⁺, Mn²⁺ single- and multiple-doped Ca₉La(PO₄)₇ (CLPO) phosphors with β-Ca₃(PO₄)₂-type structure by the simple high-temperature solid-state reaction. The crystallization behavior, crystal structure, surface morphology, photoluminescence performance, decay lifetime and thermal stability were systematically investigated. The PL spectra and decay curves have evidenced the efficient energy transfer from Ce³⁺ to Tb³⁺ and from Ce³⁺ to Mn²⁺ in the CLPO host, and corresponding energy transfer efficiency reaches 41.8% and 54.1%, respectively. The energy transfer process of Ce³⁺→Tb³⁺ and Ce³⁺→Mn²⁺ can be deduced to the resonant type via dipole-dipole and dipole-quadrupole interaction mechanism, and corresponding critical distance were determined to be 12.23 and 14.4 Å, respectively. Based on the efficient energy transfer, the white light emission can be successfully achieved in the single-component CLPO:0.15Ce³⁺, 0.10Tb³⁺, 0.04Mn²⁺ phosphor, which owns CIE chromaticity coordinates of (0.3245, 0.3347), CCT of 5878 K, internal and external quantum efficiency of 84.51% and 69.32%. Especially, compared with the emission intensity at 25 °C, it still remains 98.5% at 150 °C and 92.0% at 300 °C. Based on these results, the single-component white light emission phosphor CLPO:0.15Ce³⁺, 0.10Tb³⁺, 0.04Mn²⁺ is a potential candidate for UV-converted white LEDs.     

Dual-mode optical thermometry and multicolor anti-counterfeiting based on Bi3+/Er3+ co-activated BaGd2O4 phosphor

Here, Bi³⁺, Er³⁺ co-activated gadolinium phosphors with multimode emission properties are prepared, which can emits blue, green, and orange light under the excitation of ultraviolet, 980 and 1550 nm, respectively. Moreover, BaGd₂O₄:Bi³⁺, Er³⁺ can show multicolor luminescence under different excitation conditions, such as pump light source, ambient temperature, working current, and other factors. Based on the dynamic luminescence characteristics, the dynamic anti-counterfeiting experiments are designed based on the phosphor. At the same time, the material also shows multimode temperature sensing characteristics. Under the excitation of 980 nm laser, three strong up-conversion signals Er³⁺ ions are generated at 528 nm (²H_11/2), 555 nm (⁴S_3/2), and 668 nm (⁴F_9/2), which have different temperature dependences. Based on the fluorescence intensity ratio between thermal-coupled energy levels (²H_11/2/⁴S_3/2) and nonthermal-coupled energy levels (²H_11/2/⁴F_9/2) of Er³⁺ ions, respectively, the dual-mode temperature thermometer was constructed with high-temperature sensitivity. In addition, the fluorescence lifetime of Bi³⁺ ions also has a strong temperature dependence, which can be used as another temperature detection signal, greatly improving the stability of thermometers under harsh conditions. Therefore, the material has a bright prospect in the field of anti-counterfeiting and temperature sensing.