scholarly journals Enhancing the Relative Sensitivity of V5+, V4+ and V3+ Based Luminescent Thermometer by the Optimization of the Stoichiometry of Y3Al5−xGaxO12 Nanocrystals

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1375 ◽  
Author(s):  
Kniec ◽  
Ledwa ◽  
Marciniak
Keyword(s):  
Energy Transfer ◽  
Emission Intensity ◽  
Spectral Response ◽  
Luminescent Properties ◽  
Relative Sensitivity ◽  
Temperature Sensing ◽  
Thermal Dependence ◽  
Temperature Range

In this work the influence of the Ga3+ concentration on the luminescent properties and the abilities of the Y3Al5−xGaxO12: V nanocrystals to noncontact temperature sensing were investigated. It was shown that the increase of the Ga3+ amount enables enhancement of V4+ emission intensity in respect to the V3+ and V5+ and thus modify the color of emission. The introduction of Ga3+ ions provides the appearance of the crystallographic sites, suitable for V4+ occupation. Consequently, the increase of V4+ amount facilitates V5+ → V4+ interionic energy transfer throughout the shortening of the distance between interacting ions. The opposite thermal dependence of V4+ and V5+ emission intensities enables to create the bandshape luminescent thermometr of the highest relative sensitivity of V-based luminescent thermometers reported up to date (Smax, 2.64%/°C, for Y3Al2Ga3O12 at 0 °C). An approach of tuning the performance of Y3Al5−xGaxO12: V nanocrystals to luminescent temperature sensing, including the spectral response, maximal relative sensitivity and usable temperature range, by the Ga3+ doping was presented and discussed.

Intentional modification of the optical spectral response and relative sensitivity of luminescent thermometers based on Fe3+,Cr3+,Nd3+ co-doped garnet nanocrystals by crystal field strength optimization

2020 ◽  
Vol 4 (6) ◽  
pp. 1697-1705 ◽  
Author(s):  
K. Kniec ◽  
K. Ledwa ◽  
K. Maciejewska ◽  
L. Marciniak
Keyword(s):  
Field Strength ◽  
Crystal Field ◽  
Spectral Response ◽  
Relative Sensitivity ◽  
Temperature Range ◽  
Crystal Field Strength ◽  
Co Doped

The relative sensitivity and usable temperature range of Fe3+,Cr3+-based luminescent thermometers can be tuned by modification of the crystal field strength.

scholarly journals Controlled Synthesis of Tb3+/Eu3+ Co-Doped Gd2O3 Phosphors with Enhanced Red Emission

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 759 ◽  
Author(s):  
Dong Zhu ◽  
Jinkai Li ◽  
Xiangyang Guo ◽  
Qinggang Li ◽  
Hao Wu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Emission Intensity ◽  
Phase Variation ◽  
Hydrothermal Condition ◽  
Luminescent Properties ◽  
Excitation Wavelength ◽  
Controlled Synthesis ◽  
Energy Transfer Mechanism ◽  
Hydrothermal Conditions ◽  
Controlled Morphology

(Gd0.93−xTb0.07Eux)2O3 (x = 0–0.10) phosphors shows great potential for applications in the lighting and display areas. (Gd0.93−xTb0.07Eux)2O3 phosphors with controlled morphology were prepared by a hydrothermal method, followed by calcination at 1100 °C. XRD, FE-SEM, PL/PLE, luminescent decay analysis and thermal stability have been performed to investigate the Eu3+ content and the effects of hydrothermal conditions on the phase variation, microstructure, luminescent properties and energy transfer. Optimum excitation wavelength at ~308 nm nanometer ascribed to the 4f8-4f75d1 transition of Tb3+, the (Gd0.93−xTb0.07Eux)2O3 phosphors display both Tb3+and Eu3+ emission with the strongest emission band at ~611 nm. For increasing Eu3+ content, the Eu3+ emission intensity increased as well while the Tb3+ emission intensity decreased owing to Tb3+→Eu3+ energy transfer. The energy transfer efficiencies were calculated and the energy transfer mechanism was discussed in detail. The lifetime for both the Eu3+ and Tb3+ emission decreases with the Eu3+ addition, the former is due to the formation of resonant energy transfer net, and the latter is because of contribution by Tb3+→Eu3+ energy transfer. The phosphor morphology can be controlled by adjusting the hydrothermal condition (reaction pH), and the morphological influence to the luminescent properties (PL/PLE, decay lifetime, etc.) has been studied in detail.

scholarly journals The Luminescence Properties and Energy Transfer from Ce3+to Pr3+for YAG:Ce3+Pr3+Phosphors

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Rongfeng Guan ◽  
Liu Cao ◽  
Yajun You ◽  
Yuebin Cao
Keyword(s):  
Energy Transfer ◽  
Emission Intensity ◽  
Electronic Excitation ◽  
Light Emission ◽  
Red Light ◽  
Luminescent Properties ◽  
Concentration Increase ◽  
Transfer Phenomenon ◽  
Colour Rendering ◽  
Light Emission Intensity

Y2.94−xAl5O12(YAG):Ce0.06Prxphosphors with various Pr3+concentrations (x=0, 0.006, 0.01, 0.03, 0.06, and 0.09) were synthesized by using a coprecipitation method. The phases, luminescent properties, and energy transfer phenomenon from Ce3+to Pr3+were investigated. The results indicated that the doping of Pr3+  (x≤0.09)did not produce any new phases but caused a slight lattice parameters increase. After Pr3+doping, the YAG:CePr phosphor emits red light at 610 nm, which was regarded helpful for improving the colour rendering index of the phosphor. With Pr3+concentration increase from 0.006 to 0.01 mol, the intensity of red light emission increased slightly; further increasing Pr3+concentration from 0.01 to 0.09, the red light emission intensity decreased gradually. Excitation at 340, and 460 nm could not lead to the direct electronic excitation of Pr3+ions; however, when YAG:CePr was excited at 340 nm a red light emission at 610 nm appeared, which implied the energy transfer phenomenon from Ce3+to Pr3+.

scholarly journals Temperature sensing in Tb3+/Eu3+-based tetranuclear silsesquioxane cages with tunable emission

RSC Advances ◽  
2021 ◽  
Vol 11 (55) ◽  
pp. 34735-34741
Author(s):  
Karina Nigoghossian ◽  
Alena N. Kulakova ◽  
Gautier Félix ◽  
Victor N. Khrustalev ◽  
Elena S. Shubina ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Emission Intensity ◽  
Intensity Ratio ◽  
Temperature Sensing ◽  
Emission Intensity Ratio ◽  
Tunable Emission

Tetranuclear silsesquioxane cages with tunable thermosensitive Tb3+-to-Eu3+ energy transfer were used for temperature sensing based on the Tb3+-to-Eu3+ emission intensity ratio (LIR) with excellent linearity and sensitivity.

scholarly journals One ion to catch them all: Targeted high-precision Boltzmann thermometry over a wide temperature range with Gd3+

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Dechao Yu ◽  
Huaiyong Li ◽  
Dawei Zhang ◽  
Qinyuan Zhang ◽  
Andries Meijerink ◽  
...  
Keyword(s):  
Wide Temperature Range ◽  
Thermal Sensitivity ◽  
Energy Levels ◽  
Relative Sensitivity ◽  
Black Body ◽  
Temperature Sensing ◽  
Lanthanide Ions ◽  
Visible Range ◽  
Temperature Range ◽  
Luminescence Thermometry

AbstractRatiometric luminescence thermometry with trivalent lanthanide ions and their 4fn energy levels is an emerging technique for non-invasive remote temperature sensing with high spatial and temporal resolution. Conventional ratiometric luminescence thermometry often relies on thermal coupling between two closely lying energy levels governed by Boltzmann’s law. Despite its simplicity, Boltzmann thermometry with two excited levels allows precise temperature sensing, but only within a limited temperature range. While low temperatures slow down the nonradiative transitions required to generate a measurable population in the higher excitation level, temperatures that are too high favour equalized populations of the two excited levels, at the expense of low relative thermal sensitivity. In this work, we extend the concept of Boltzmann thermometry to more than two excited levels and provide quantitative guidelines that link the choice of energy gaps between multiple excited states to the performance in different temperature windows. By this approach, it is possible to retain the high relative sensitivity and precision of the temperature measurement over a wide temperature range within the same system. We demonstrate this concept using YAl3(BO3)4 (YAB):Pr3+, Gd3+ with an excited 6PJ crystal field and spin-orbit split levels of Gd3+ in the UV range to avoid a thermal black body background even at the highest temperatures. This phosphor is easily excitable with inexpensive and powerful blue LEDs at 450 nm. Zero-background luminescence thermometry is realized by using blue-to-UV energy transfer upconversion with the Pr3+−Gd3+ couple upon excitation in the visible range. This method allows us to cover a temperature window between 30 and 800 K.

scholarly journals LiAl5O8:Fe3+ and LiAl5O8:Fe3+, Nd3+ as a New Luminescent Nanothermometer Operating in 1st Biological Optical Window

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 189 ◽  
Author(s):  
Karolina Kniec ◽  
Marta Tikhomirov ◽  
Blazej Pozniak ◽  
Karolina Ledwa ◽  
Lukasz Marciniak
Keyword(s):  
High Temperatures ◽  
Emission Intensity ◽  
Biological Systems ◽  
Relative Sensitivity ◽  
Temperature Sensing ◽  
Optical Window ◽  
Wide Range ◽  
Cytotoxicity Assessment ◽  
First Time

New types of contactless luminescence nanothermometers, namely, LiAl5O8:Fe3+ and LiAl5O8:Fe3+, Nd3+ are presented for the first time, revealing the potential for applications in biological systems. The temperature-sensing capability of the nanocrystals was analyzed in wide range of temperature (−150 to 300 °C). The emission intensity of the Fe3+ ions is affected by the change in temperature, which induces quenching of the 4T1 (4G) → 6A1 (6S) Fe3+ transition situated in the 1st biological window. The highest relative sensitivity in the temperature range (0 to 50 °C) was found to be 0.82% °C (at 26 °C) for LiAl5O8: 0.05% Fe3+ nanoparticles that are characterized by long luminescent lifetime of 5.64 ms. In the range of low and high temperatures the Smax was calculated for LiAl5O8:0.5% Fe3+ to be 0.92% °C at −100 °C and for LiAl5O8:0.01% Fe3+ to be 0.79% °C at 150 °C. The cytotoxicity assessment carried out on the LiAl5O8:Fe3+ nanocrystals, demonstrated that they are biocompatible and may be utilized for in vivo temperature sensing. The ratiometric luminescent nanothermometer, LiAl5O8:Fe3+, Nd3+, which was used as a reference, possesses an Smax = 0.56%/°C at −80 °C, upon separate excitation of Fe3+ and Nd3+ ions using 266 nm and 808 nm light, respectively.

scholarly journals Down-Shifting in the YAM: Ce3+ + Yb3+ System for Solar Cells

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2753
Author(s):  
Bartosz Fetliński ◽  
Sebastian Turczyński ◽  
Michał Malinowski ◽  
Paweł Szczepański
Keyword(s):  
Energy Transfer ◽  
Emission Intensity ◽  
Potential Application ◽  
Single Photon ◽  
Solar Spectrum ◽  
Excitation Power ◽  
Photovoltaic Devices ◽  
Photoluminescence Properties ◽  
System A ◽  
Down Conversion

In this work, we investigate Ce3+ to Yb3+ energy transfer in Y4Al2O9 (YAM) for potential application in solar spectrum down-converting layers for photovoltaic devices. Photoluminescence properties set, of 10 samples, of the YAM host activated with Ce3+ and Yb3+ with varying concentrations are presented, and the Ce3+ to Yb3+ energy transfer is proven. Measurement of highly non-exponential luminescence decays of Ce3+ 5d band allowed for the calculation of maximal theoretical quantum efficiency, of the expected down-conversion process, equal to 123%. Measurements of Yb3+ emission intensity, in the function of excitation power, confirmed the predominantly single-photon downshifting character of Ce3+ to Yb3+ energy transfer. Favorable location of the Ce3+ 5d bands in YAM makes this system a great candidate for down-converting, and down-shifting, luminescent layers for photovoltaics.

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