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1.
《Ceramics International》2016,42(12):14086-14093
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 4G5/2 state of Sm3+ to 5D0 state of Eu3+ rather than 5D1 of Eu3+ ions. 相似文献
2.
《Ceramics International》2020,46(13):20664-20671
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 2H11/2-4I15/2 and 4S3/2-4I15/2 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. 相似文献
3.
Different luminescent behaviors of La3NbO7:Sm3+ phosphors under the excitations of charge transfer band (CTB, 250 nm) and featured absorption peak (6H5/2 → 4H7/2, 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 (λex =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 4G5/2 → 6H9/2 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. 相似文献
4.
《Ceramics International》2022,48(3):3051-3058
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 Ba3-xSrxLu4O9 (B3-xSxLO):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 2H11/2/4S3/2, FIR based on non-thermally coupled system of 2H11/2/4F9/2 and fluorescence lifetime of 4S3/2 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 B3-xSxLO:Er3+/Yb3+ for thermometry. 相似文献
5.
《Ceramics International》2016,42(5):5737-5742
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. 相似文献
6.
《Ceramics International》2016,42(12):13919-13924
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. 相似文献
7.
《Ceramics International》2022,48(20):30005-30011
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 (Sa) and relative sensitivity (Sr) 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. 相似文献
8.
JunYu Chen LianJie Li Tao Pang Hai Guo LiPing Chen 《Journal of the American Ceramic Society》2023,106(12):7514-7522
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 (SR) 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, SR values of FI and FIR modes decrease slowly. Their minimal SR 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. 相似文献
9.
Qi Xiao Xinyao Dong Xiumei Yin Hong Wang Weiguang Yu Hua Zhong Mingming Xing Ying Tian Yao Fu Bin Dong Xixian Luo 《Journal of the American Ceramic Society》2021,104(1):263-272
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. 相似文献
10.
《Ceramics International》2022,48(11):15755-15761
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. 相似文献
11.
《Ceramics International》2016,42(15):16499-16504
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). 相似文献
12.
《Ceramics International》2015,41(7):8988-8995
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 Ba1.90Ce0.04Na0.04Eu0.02Mg0.94Tb0.06(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. 相似文献
13.
Chunyan Xie Lu Zhao Bin Jiang Jiashan Mao Yan Lin Peng Wang Xiantao Wei Min Yin Yonghu Chen 《Journal of the American Ceramic Society》2019,102(12):7500-7508
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. 相似文献
14.
《Ceramics International》2022,48(13):18157-18164
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. 相似文献
15.
《Ceramics International》2022,48(3):3860-3868
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 Sr 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. 相似文献
16.
《Ceramics International》2019,45(10):13235-13241
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. 相似文献
17.
Li Li Peixin Yang Weidi Xia Yongjie Wang Faling Ling Zhongmin Cao Sha Jiang Guotao Xiang Xianju Zhou Yan Wang 《Ceramics International》2021,47(1):769-775
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. 相似文献
18.
Preparation,luminescence properties and energy transfer of Ca9Y(PO4)7: Eu2+‐Tb3+ phosphors
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Miao Tang Yanting Fan Zhongxian Qiu Jilin Zhang Liping Yu Chengzhi Li Shixun Lian Wenli Zhou 《Journal of the American Ceramic Society》2017,100(7):2991-2996
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. 相似文献
19.
Xiaoyi Fan Jiayong Si Mengjie Xu Guihua Li Jiamin Tang Gemei Cai 《Ceramics International》2021,47(9):12056-12065
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. 相似文献
20.
Jie Fu Liuyan Zhou Yanling Chen Jianhua Lin Renguang Ye Lei Lei Yang Shen Degang Deng Shiqing Xu 《Journal of the American Ceramic Society》2023,106(2):1333-1343
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 (2H11/2), 555 nm (4S3/2), and 668 nm (4F9/2), which have different temperature dependences. Based on the fluorescence intensity ratio between thermal-coupled energy levels (2H11/2/4S3/2) and nonthermal-coupled energy levels (2H11/2/4F9/2) 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. 相似文献