Single-doped Samples Research Articles

Photoluminescence Properties and Energy Transfers in the Novel LiYMgWO6: Dy3+, Tm3+

A series of Dy3+/Tm3+ single doped and co-doped double perovskite-structure compound LiYMgWO6 (LYMW) are prepared by a solid-state route. The structure and photoluminescence properties have been unraveled by combining experiments and first-principles calculations. The crystal structure was determined to be a monoclinic structure with space groups P21. Under the ultraviolet (UV) excitation, Dy3+ and Tm3+ single doped LYMW samples emit yellowish-white and blue light, respectively. For Dy3+ and Tm3+ co-doped LYMW, the emission can be tuned from blue to white light and eventually to yellow through energy transfers by varying the Dy3+ and Tm3+ concentrations. The sample with 3%Dy3+ and 3%Tm3+ has chromaticity coordinates (0.3405, 0.3378), which are nearest to the ideal white light (0.33,0.33). The energy transfer mechanism is verified to be the quadrupole-quadrupole interaction. The temperature-dependent photoluminescence (PL) spectra show that LYMW: Dy3+, Tm3+ exhibits good thermal stability.

High quantum efficiency and thermal stability Sr3LiNbO6:Mn4+, Zn2+ phosphors for application in indoor plant growth lighting

New double perovskite Sr3LiNbO6:x%Mn4+ and Sr3LiNbO6:x%Mn4+, 1.25x%Zn2+ far-red-emitting phosphors were reported for the first time. The phosphors were characterized by XRD, SEM, PL, PLE, UV–vis spectroscopy, CIE color coordinate and internal quantum efficiency (IQE) measurements. Under the excitation of 365 nm light, Sr3LiNbO6:x%Mn4+ phosphors show a strong far-red emission peak at 695 nm, which is suitable for use in indoor plant application. Furthermore, by co-doping of Zn2+ ions, a more homogeneous particle size distribution was obtained and the emission intensity can raise up to 1.29 times that of Mn4+ single-doped samples. The Sr3LiNbO6:0.6%Mn4+, 0.75%Zn2+ phosphor can obtain an IQE of 78.4% and an emission intensity of 80.6% at 423 K from that at 284 K, showing a high luminous efficiency and thermal stability. Finally, a LED lamp was fabricated with the use of far-red-emitting optimized phosphor, which shows an effective promotion on growth rate and content of photosynthesis pigments of wheat. The results show that Sr3LiNbO6:Mn4+, Zn2+ phosphors may have a promising future in the field of agriculture cultivations.

Scintillation properties of Ce3+/Tb3+ co-doped oxyfluoride aluminosilicate glass for exploration of X-ray imaging

Ce3+ or Tb3+ single-doped and Ce3+/Tb3+ co-doped oxyfluoride scintillation glass samples were prepared by high temperature melting method. The structures were analyzed by X-ray diffraction (XRD), the optical and luminescent properties were studied by transmittance, photoluminescence excitation, photoluminescence, X-ray excited luminescence (XEL) and fluorescence decay. The luminescence intensity in the Ce3+/5 mol% Tb3+ co-doped (CT5) glass sample under 304 nm light and X‐ray excitation is significantly enhanced compared to 5 mol% Tb3+ single-doped (T5) glass sample. The maximum integrated XEL intensity of CT5 glass sample is about 67% of the standard Bi4Ge3O12 (BGO) crystal. Through the study of energy transfer mechanism, the results indicate that there is an energy transfer from Gd3+ ions or Ce3+ ions to Tb3+ ions. The lifetime of CT5 glass sample is 2.13 ms. The obtained results confirm that CT5 glass sample could be a promising scintillating material used in X-ray imaging. So we have demonstrated X-ray imaging using Ce3+/1–15 mol% Tb3+ co-doped (CT1-15) glass samples and confirmed they can reach a spatial resolution of 10.0 lp/mm. Further, the X-ray imaging effect of CT5 glass sample is the best, and the capability of CT5 glass sample for X-ray imaging application is confirmed.

Cubic structured SrTiO3 with Ce/Cr Co-doping for photoinduced catalytic oxidation of gaseous mercury

A cubic SrTiO3 (STO) composite material co-doped with Ce and Cr ions was synthesized by solvothermal method. The fully characterized samples were employed as photocatalysts for the oxidation of Hg0. The co-doped samples afforded excellent catalytic removal efficiency of 98.99% using UV irradiation and 89.9% using visible light irradiation for Hg0 compared with the single-doped samples. It was found that co-doped samples had a lower electron-hole recombination rate, largest Brunauer-Emmett-Teller specific surface area, and reduced band gap. The electron spin resonance results revealed that ·O2− and ·OH were the main active species in the catalytic process. Moreover, the co-doped samples exhibited the best electron transfer rate and the highest photocurrent response intensity. The electron transfer between the elements in the co-doped sample enables it to achieve stable and efficient catalytic performance. In addition, even after five consecutive catalytic runs, the co-doped sample maintained high catalytic activity. This work highlights the potential of the perovskite-type STO materials in the photocatalytic oxidation of gaseous mercury.

Enhancing blue light absorption by Sm3+ Co-doing in Ca9Nd(PO4)7: Eu3+ for white light-emitting diodes

White light-emitting diodes (WLEDs) is widely concerned as the next-generation source of displays and lighting on account of many advantages. In this work, Sm3+ ions were introduced into Ca9Nd(PO4)7: Eu3+ (CNPO: Eu3+) red phosphors as a co-dopant to boost the blue-light excitation. X-ray diffraction (XRD) data confirm the successful preparation of the materials. Rietveld refinements were employed to investigate the site occupation and lattice parameter variation. All obtained materials have showed red emission under blue light or near-ultraviolet light excitation. The photoluminescence (PL) emission spectra features both signals from the two dopants, and the introduction of Sm3+ could effectively boost the red-light emission and blue-light excitation. Theoretical simulations help evidence the capability of the CNPO materials as host matrix of luminescent centers. Finally, a blue LED chip-based WLED was assembled in demonstration of their potential applications. Compared to the controlling device made with Eu3+ single-doped samples, the co-doped one has stronger blue light excitation and red light emission that guarantees a high luminous efficacy of over 90 lm W−1. The device also shows a superb long-term stability under continuous working. All in all, the CNPO: Eu3+, Sm3+ phosphors have shown many promising aspects in blue chip-based WLED applications.

Temperature-dependent luminescence properties of Dy3+, Tm3+ single-/co-doped YNbO4 phosphors

Dy3+, Tm3+ single-/co-doped YNbO4 phosphors were prepared by a high temperature solid-state reaction method. Rietveld refinement analysis was performed to reveal the phase formation and the doping-induced change of the lattice parameters. The results revealed that monoclinic YNbO4 phosphors were obtained. From temperature-dependent emission spectra, it was found that the total intensities of the emissions of Dy3+ and Tm3+ decreased with increasing temperature, and a new peak originated from 4I15/2→6H15/2 transition of Dy3+ appeared at higher temperatures, and its intensity increased with temperature elevation. The temperature sensing properties of both Dy3+ single-doped and Dy3+, Tm3+ co-doped phosphors were studied. A new model was proposed to describe the temperature dependence of the fluorescence intensity ratio (FIR) of the 456 nm emission to the 487 nm emission in Dy3+, Tm3+ co-doped sample. It was discovered that the sensitivity of Dy3+ single-doped YNbO4 sample was similar with that of Dy3+, Tm3+ co-doped one. Moreover, the chromatic stability versus sample temperature was evaluated according to their color coordinates.

Enhanced Near-Infrared Luminescence in Ba3Y(BO3)3: Nd3+ by Codoping with Ce3+

Silicon solar cells are still dominating the solar cell market due to its mature technology, but its efficiency was limited due to its ineffective response to solar spectrum. Phosphor could modify the solar spectrum by transferring the Sunlight that cannot be effectively used to optimal response range of silicon solar cell. Here, Ba3Y(BO3)3: Ce3+, Nd3+ with near-infrared (NIR) emission were prepared via solid-state reaction route, which offer wide blue-violet light of Ce3+ ions and intense near-infrared light of Nd3+ ions locating at the maximal spectral response of silicon solar cell. The near-infrared emission intensity of Ce3+-Nd3+ sample was increased in comparison with that of Nd3+ single-doped sample, which show that Ce3+ act as an efficient sensitizer with broad absorption cross-section. The energy transfer mechanism was also analyzed. Results reveal that Ba3Y(BO3)3: Ce3+, Nd3+ co-doped phosphor have promising applications as solar spectral convertor for silicon-based solar cells.

Meticulous guard: The role of Al/F doping in improving the electrochemical performance of high-voltage spinel cathode

Spinel LiNi0.5Mn1.5O4, which is considered as one of the most attractive candidates for high energy density battery due to its high voltage platform over 4.7 V, suffers from the side reactions with electrolyte, strong oxidability of Ni4+ and therefore the complicated and frangible Solid Electrolyte Interfaces (SEI) layer that hinders the practical application of LiNi0.5Mn1.5O4. In this work, traditional co-precipitation method is applied and improved by anion and cation doping method to construct superior interface on the surface of LiNi0.5Mn1.5O4 to suppress side reactions especially at high temperature. Detailed properties including structure, morphology and electrochemical performance of pristine sample, single-doped and co-doped samples are probed. Physical characterizations reveal that the co-doped sample with regular octahedron has a moderate grain size and specific surface area between Al and F single doping, and holds the advantages of rate performance and capacity retention causing by Al doping and better stability under high temperature constructing by F. It exhibits the best capacity retention of 92% after 200 cycles under 55 °C, which is higher than that of the pristine sample (87%). Analysis of the electrode after cycling shows that doping reduces the thickness of the electrode interface film and the content of inorganic substances such as LiF to improve the interface characteristics and the high temperature cycling performance. This work has certain significance for the commercial application of LiNi0.5Mn1.5O4.

Emission-tunable Sr8.5-mMg2+m(PO4)7:Eu2+/Mn2+ phosphors for multifunctional applications

A series of Sr8.5-mMg2+m(PO4)7:Eu2+,Mn2+ (m = 0 and ±0.5) phosphors were prepared by solid-state reaction. The phase purity, luminescence properties and thermal stability were investigated systematically. Under 365 nm excitation, the Sr8.5-mMg2+m(PO4)7:Eu2+ exhibits a wide emission band covering from 425 to 850 nm with three main peaks centered at 412, 515 and 625 nm, which are attributed to the 4f65 d1→4f7 transitions of Eu2+ in different crystallographic sites. The emission color can be tuned by changing the concentrations of Mg2+, Eu2+ and Mn2+. To obtain white-emitting light, the Eu2+-Mn2+ co-doped samples were designed, in which an energy transfer from Eu2+ to Mn2+ was found. On the other hand, the fluorescence intensity ratio (FIR) technique was utilized in the Eu2+-single-doped sample for optical temperature-sensing. The high absolute and relative sensitivities were achieved. The above investigations indicate that the developed phosphors could show multi-functional applications in white LEDs and optical thermometers.

Structural and optical properties of Dy3+:YAlO3 phosphors for yellow light-emitting diode applications

The spectroscopic properties of a series of Dy3+ single-doped and Dy3+/Nd3+, Dy3+/Tb3+, and Dy3+/Tm3+ co-doped YAlO3 (yttrium aluminum perovskite, YAP) phosphors were investigated and compared through the measurements of optical absorption, emission spectra, and fluorescence decay curves. For the Dy3+ ion single-doped samples, the intensity of each absorption band increases with an increment in Dy3+ ion doping concentration, and the identified strong absorption peak at 447 nm indicates that Dy3+:YAP phosphors are suitable to be pumped by a blue laser diode (LD). For all co-doped samples, absorption peaks of Dy3+ ion along with some of the absorption bands of Nd3+, Tb3+, and Tm3+ ions are observed. Under 351 and 447 nm excitation, a prominent emission peak at 572 nm was obtained in all the samples, corresponding to Dy3+: 4F9/2 → 6H13/2 transition. Here, 2 at% Dy3+:YAP phosphor exhibits the highest yellow emission intensity under 447 nm pumping. Among the three kinds of Dy3+ co-doped phosphors, Dy3+/Tb3+:YAP phosphor possesses the dominant yellow emission. The fluorescence decay curves show exponential behaviour and are fitted well. The Commission International de L'Eclairage (CIE) chromaticity coordinates were calculated following the respective emission spectra, and it is found that all the coordinates locate in the yellow region. The energy transfer (ET) processes were investigated and the concentration quenching mechanism was discussed. The obtained results suggest that Dy3+-activated YAP phosphors are good candidates for yellow LED applications.

Aluminum and phosphorus codoped “superaerophobic” Co3O4 microspheres for highly efficient electrochemical water splitting and Zn-air batteries

Abstract Multifunctional non-precious catalysts for hydrogen/oxygen evolution reaction (HER/OER) and oxygen reduction reaction (ORR) constitute the bottleneck in the applications in electrochemical overall water splitting (OWS) and Zn-air batteries. Herein, a trifunctional electrocatalyst of urchin-like Al,P-codoped Co3O4 microspheres supported on Ni foam (denoted as AP-CONPs/NF) was fabricated via a hydrothermal process and subsequent low-temperature annealing and phosphorization, exhibiting enhanced OER, HER and ORR activities compared with single-doped and undoped samples. Their surface self-organized microstructure and excellent “superaerophobic” feature make a high bubble repellency, which boost diffusion of reactants and electrolyte-electrode intimate contact. The codoping of Al and P elements into Co3O4 betters right the balance among surface chemical state, the increased oxygen vacancies and the promoted charge transfer. Encouraged by these synergistic advantages, the AP-CONPs/NF was further employed as excellent bifunctional electrodes for the OWS (low cell voltage of 1.57 V at 10 mA cm−2) and as air cathode for rechargeable Zn-air batteries (high power density of 89.1 mW cm−2), which demonstrates a great feasibility for practical applications.

High Thermoelectric Performance of Co-Doped P-Type Polycrystalline SnSe via Optimizing Electrical Transport Properties.

This work systematically investigated the thermoelectric properties of p-type Na and M (M = K, Li, Ag) codoped polycrystalline SnSe. It is found that the electrical properties of polycrystalline SnSe can be improved significantly for (Na, Ag) codoped samples, contributed by the enhanced carrier concentration. Specifically, a carrier concentration of 6.23 × 1019 cm-3 was obtained in Sn0.98Na0.016Ag0.004Se sample at 335 K, an increase of 18% compared with that of the Na single-doped sample (5.22 × 1019 cm-3). The power factor reached ∼0.73 mW m-1 K-2 for the Sn0.98Na0.016Ag0.004Se sample at 785 K, enhanced by ∼26% compared with Na single-doped one. In addition, Sn-rich and Ag-rich particles/areas observed in the matrix of Sn0.98Na0.016Ag0.004Se contribute to the reduction of lattice thermal conductivity from 0.61 W m-1 K-1 for Sn0.98Ag0.02Se to 0.47 W m-1 K-1 at 785 K. The combination of simultaneously enhanced power factor and depressed thermal conductivity leads to a maximum ZT ≈ 1.2 at 785 K and a high average ZT ≈ 0.74 at 335-785 K for Sn0.98Na0.016Ag0.004Se, and generating a high theoretical conversion efficiency of ∼11%. These illuminating discoveries could provide routes to enhance the thermoelectric performance in p-type polycrystalline SnSe.

Structural studies and photocatalytic properties of Mn and Zn co-doping on TiO2 prepared by single step sonochemical method

Titanium dioxide nanoparticles dual doped with zinc and manganese were prepared by the single step of sonochemical method using the sonicator with 20 kHz and 750 W for 30 min. Phase structure analysis results showed that the pure anatase phase was detected for all prepared samples. TEM analysis reveals the nanosized structure with uniformity of nanoparticles. The calculated bandgap energies change to be below the typical band gap energy of bare TiO2 and single doped sample suggesting high ability to harvest visible light. X-ray absorption spectroscopy was conducted to investigate the electronics structure and to study the local structure of prepared samples. XANES results confirmed the existence of Ti4+ ions in all prepared samples with anatase crystal structure. EXAFS analysis indicates the Ti4+ site was substituted by Mn and Zn dopant ions. The photocatalytic performance was evaluated by degradation of Rhodamine B dye solution under visible light irradiation. The results revealed that the dually Mn–Zn doped TiO2 sample exhibited excellent photocatalytic activity comparing to single doped and pure TiO2. The complete degradation of dye was achieved at optimum condition of 1 mol%-Zn and 2 mol%-Mn molar ratio. The highest photodegradation rate constant was found to be 0.0238 min−1, which is 10 times greater than pure-TiO2 samples.

Outstanding supercapacitor performance of Nd–Mn co-doped perovskite LaFeO3@nitrogen-doped graphene oxide nanocomposites

Perovskites have been significantly considered as promising materials for electrochemical energy storage in the recent years. Co-doping of Mn and Nd with hydrothermally synthesized LaFeO3 (LF) perovskite resulted in La0.8Nd0.2Fe0.8Mn0.2O3 (LNFM) with significantly higher specific capacitance of 158 F/g at 50 mV/s compared to non-doped and single doped LF samples. Subsequently, LNFM/nitrogen-doped graphene oxide (NGO) nanocomposite was prepared and investigated. It was found out that the introducing of NGO substantially enhances the specific capacitance of the nanocomposite up to 1060 F/g at 50 mV/s. Besides, the composite revealed outstanding capacity retention as 92.4% after 10000 continuous cycle (85.37% for the LNFM sample). In overall, the electrochemical behavior of the composite with 1:1 ratio of LNFM/NGO confirms its high potential as supercapacitor for energy storage applications.

Effect of dopant concentration on structural and optical properties of Cd0.7Zn0.3S semiconducting nanocrystals

Cu single doped and Cu, Mn co-doped Cd0.7Zn0.3S nanocrystals were synthesized successfully by co-precipitation method. XRD results confirmed hexagonal structure of as prepared Cu single doped and Cu, Mn co-doped Cd0.7Zn0.3S samples. The lattice constants, lattice plane, d-spacing, unit cell volume, Lorentz factor and dislocation density were also determined. The SEM analysis shows aggregation and nonuniform shapes of nanoparticles. The EDX spectra indicate the presence of S, Cd, Zn, Cu, Mn along with N and O in our samples. Absorption spectra shows maximum absorption in the range 209–236 nm with a shoulder peak at 277–299 nm which confirms a blue shift in comparison to bulk spectra. The photoluminescence (PL) spectra of Cu single doped samples shows blue-green emission centered at 428 and 488 nm. In Cu, Mn co-doped samples, higher intensity in blue green region at 458 and 488 nm attributed due to the sulfur vacancy and Zn defects respectively.

Boosting Thermoelectric Performance of SnSe via Tailoring Band Structure, Suppressing Bipolar Thermal Conductivity, and Introducing Large Mass Fluctuation.

Here, we report a peak ZT of 1.85 at 873 K for sulfur and Pb codoped polycrystalline SnSe by boosting electrical transport properties while suppressing the lattice thermal conductivity. Compared with single sulfur doped samples, the carrier concentration is improved 1 order of magnitude by Pb incorporation, thereby contributing to improved electrical conductivity and power factor. Moreover, the introduction of sulfur and Pb suppresses the bipolar thermal conductivity by enlarging the band gap. The lattice thermal conductivity significantly decreased as low as 0.13 W m-1 K-1 at 873 K due to the synergic approach involving suppressing bipolar thermal conductivity, large mass fluctuation induced by sulfur incorporation, and nanoprecipitates. We demonstrate that the combination of tailoring band structure, suppressing bipolar thermal conductivity, and introducing large mass fluctuation contributes to the high thermoelectric performance in SnSe. The high performance was achieved through boosting electrical transport properties while maintaining ultralow thermal conductivity. Our findings offer a new strategy for achieving high performance thermoelectric materials.

Broadband excitation of Eu3+, Bi3+ co-doped GdNbTiO6 red phosphors with good color purity

Eu3+ single-doped and Eu3+, Bi3+ co-doped GdNbTiO6 phosphors were synthesized by high temperature solid-state reaction method. The crystal structure of the samples was analyzed by means of X-ray diffraction. Strong red emission at 615 nm with good color purity was observed in GdNbTiO6: Eu3+, Bi3+ system under excitations of a wide region of ultraviolet light. Investigation on Eu3+-concentration dependent luminescence of Eu3+ single-doped samples revealed that exchange interaction between Eu3+ ions was responsible for the concentration quenching of Eu3+. Efficient energy transfers from Bi3+ to Eu3+ have been proved by using the spectra. The introduction of Bi3+ effectively extended the excitation band of Eu3+ in the near-ultraviolet region. However, it almost had no effect on the line shape and peak positions of Eu3+ emission spectra. Luminescence thermal quenching behavior was observed in both Eu3+ single-doped and Eu3+, Bi3+ co-doped GdNbTiO6 phosphors, which can be ascribed to the crossover process.

Realization of n-type BiCuSeO through Co doping

We investigated the physical properties of the cobalt doped layered oxyselenides BiCu1-xCoxSeO. 5% Co doping led to a large increase in the Seebeck coefficient which should be attributed to the magnetic interactions with the magnetic moment carried by Co atoms. The carrier-type of the material is changed from p-type to n-type with 20% Co doping. We studied the thermoelectric property of Bi0.95Ca0.05Cu0.95Co0.05SeO. The dual-doping sample exhibits higher Seebeck coefficient than Ca single doped sample and the ZT was enhanced remarkably. A maximum ZT value of 0.11 was achieved for Bi0.95Ca0.05Cu0.95Co0.05SeO at 300 K.

Synthesis and luminescence properties of single-phase Ca2P2O7:Eu2+, Eu3+ phosphor with tunable red/blue emission

A series of Eu2+ and Eu3+ coexisting Ca2P2O7 phosphors with tunable red/blue (R/B) emission have been successfully synthesized by a two-step method. Phase composition, luminescence properties and surface states are investigated by the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) emission spectra, fluorescence quantum efficiency, fluorescent lifetime and X-ray photoelectron spectroscopy (XPS). It can be concluded from XRD and FTIR results that pure Ca2P2O7 phase can be obtained at 900 °C and Ca3(PO4)2 impurity phase occurs at an increasing preparation temperature (1100 °C). The XRD results confirm that the Eu2+or Eu3+ doped samples all exhibit pure tetragonal Ca2P2O7 crystal with space group P41. Under excitation of 330 nm, Eu2+ singly-doped Ca2P2O7 phosphors showed a broad blue emission band at 422 nm, while the Eu3+ single-doped samples emitted a strong orange-red light with wavelength of 591, 597 and 618 nm excited by 395 nm. In particular, oxygen vacancies in pure Ca2P2O7 crystal are found due to the strong PL emission at 420 nm. Furthermore, Eu2+/Eu3+ co-doped Ca2P2O7 phosphors prepared by this two-step synthesis show the blue emission at 422 nm (Eu2+ ions) and the orange-red emission (Eu2+ ions) at 591 nm, 597 nm and 618 nm under near-ultraviolet (NUV) excitation of 380 nm. It was detected that the quantum efficiency of the Ca1.88P2O7:0.12Eu phosphor was 37.7%. The tunable R/B emission ratio from 0.13 to 1.56 can be achieved by controlling the recalcined temperature in the second step when excited by 380 nm. The XPS demonstrate the existence of Eu3+ ions on the surface of Eu2+/Eu3+ co-doped Ca2P2O7 phosphors. Under NUV excitation in the range from 350 to 400 nm, the optimum Commission International de I’Eclairage (CIE) coordinate of Ca2P2O7:0.12Eu2+/Eu3+ phosphors is (0.3648, 0.215), which can be potentially used as an emitting source to meet the needs of illumination devices.

Temperature-dependent luminescence of BaLaMgNbO6:Mn4+, Dy3+ phosphor for dual-mode optical thermometry

We have co-doped Mn4+ and Dy3+ into a perovskite structure host BaLaMgNbO6 (BLMN) in order to develop a new scheme of dual-mode optical thermometry. All the samples including single-doped and co-doped samples were successfully synthesized via a high-temperature solid-state reaction method. The phase purity and luminescence properties of the phosphors were characterized by X-ray powder diffraction, photoluminescence excitation and emission spectra. In particular, temperature-dependent emission spectra as well as luminescence decay curves measurements were performed on the co-doped BLMN:Mn4+, Dy3+ sample to inspect its temperature-dependent luminescence properties. Under 355 nm excitation, the fluorescence intensity ratio (FIR) between Dy3+ emission at 580 nm (4F9/2 → 6H13/2) and Mn4+ emission at 698 nm (2Eg→4A2g) as well as the fluorescence lifetime of Mn4+ (2Eg→4A2g) were investigated in the temperature range from 230 K to 470 K, and the maximum relative sensitivities are 1.82% K−1 at 457 K and 2.43% K−1 at 437 K, respectively. It should be noted that the emission peak of Mn4+ whose luminescence can be employed by lifetime-mode temperature sensing is located in the optical window of biological tissue, which could be used in biological application. All these investigations suggest that the BLMN:Mn4+, Dy3+ phosphor is very promising in dual-mode high-sensitivity optical thermometry.