Integrating Positive and Negative Thermal Quenching Effect for Ultrasensitive Ratiometric Temperature Sensing and Anti-counterfeiting

2021 ◽  
Author(s):  
Yubin Wang ◽  
Lei Lei ◽  
Renguang Ye ◽  
Guohua Jia ◽  
Youjie Hua ◽  
...  
Keyword(s):  
Thermal Quenching ◽  
Temperature Sensing ◽  
Quenching Effect

Thermoluminescence study on TlGaSSe layered single crystals

2014 ◽  
Vol 28 (16) ◽  
pp. 1450133 ◽  
Author(s):  
Serdar Delice ◽  
Nizami M. Gasanly
Keyword(s):  
Single Crystals ◽  
Heating Rate ◽  
Thermal Quenching ◽  
Activation Energies ◽  
Temperature Peak ◽  
Heating Rates ◽  
Quenching Effect ◽  
Defect Centers ◽  
General Order ◽  
Maximum Temperatures

The defect centers in TlGaSSe single crystals have been investigated by performing thermoluminescence (TL) measurements with various heating rates between 0.5 K/s and 1.0 K/s in the temperature range of 10–180 K. The TL spectra, with peak maximum temperatures at 39 K and 131 K, revealed the existences of two defect levels. Curve fitting, initial rise and peak shape methods were used to determine the activation energies of two defect centers. The experimental results also showed that the trapping process was dominated by second-order kinetics for the trap related with low temperature peak while the general order (mixed order) kinetics was dominant for the trap donated to high temperature peak. Furthermore, heating rate dependences and traps distributions were studied for two defect centers separately. Thermal quenching effect dominates the behavior of these defects as the heating rate is increased. Also, quasi-continuous distributions were established with the increase of the activation energies from 16 meV to 27 meV and from 97 meV to 146 meV for the traps associated with the peaks observed at low and high temperatures, respectively.

scholarly journals Photoluminescent Properties of Hydrogenated Amorphous Silicon Oxide Powders

2002 ◽  
Vol 17 (5) ◽  
pp. 977-980 ◽  
Author(s):  
Wei-Fang Su ◽  
Hong-Ru Guo
Keyword(s):  
Amorphous Silicon ◽  
Silicon Oxide ◽  
Hydrogenated Amorphous Silicon ◽  
Thermal Quenching ◽  
Amorphous Semiconductors ◽  
Electronic Density ◽  
Quenching Effect ◽  
Oxide Powders ◽  
Amorphous Silicon Oxide ◽  
Hydrogenated Amorphous

The photoluminescence properties of hydrogenated amorphous silicon oxide powder SiO0.92H0.53 were investigated. The powder was prepared by reacting lithium with trichlorosilane in tetrahydrofuran. The luminescence peak energy was located between 1.0 and 1.61 eV. The samples were treated under different conditions such as annealing, hydrolysis, and hydrolysis plus HF etching. The changes of the photoluminescent intensity and location on the treated powders can be explained by the electronic density of state model of amorphous semiconductors. The temperature dependence of luminescence properties of the powders can be described by the relationship of thermal quenching effect: ln[Io/I(T) – 1] = ED/Eo = T/To at temperatures between 100 and 300 K.

scholarly journals (Ce, Gd):YAG-Al2O3 composite ceramics for high-brightness yellow light-emitting diode applications

2021 ◽  
Author(s):  
Xiaoyun Li ◽  
Jian Chen ◽  
Zhuguang Liu ◽  
Zhonghua Deng ◽  
Qiufeng Huang ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Thermal Quenching ◽  
Second Phase ◽  
Composite Ceramics ◽  
Vacuum Sintering ◽  
Phosphor Material ◽  
High Brightness ◽  
Light Emitting ◽  
Quenching Effect ◽  
Noticeable Improvement

Abstract Gd3+ ions were doped in Ce:YAG ceramics as the phosphor material for the high-brightness yellow LED (565-590 nm). Besides the role of spectral modulation, the introduction of Gd3+ ions also exacerbates the thermal quenching effect. To increase its thermal performance, Al2O3 were introduced as the second phase and (Ce0.6%Y69.4%Gd30%)3Al5O12-z% Al2O3 (z=0, 10, 20, 30, 40) composite ceramics were fabricated by vacuum sintering. Their composite microstructures and phase structures were characterized. As the amount of Al2O3 increases from 0 wt% to 40 wt%, there is a noticeable improvement on the thermal conductivity. The thermal stability also increases and the operating temperature of ceramics reduced from 141.1 °C to 132.2 °C. Collaborating composite ceramics with InGaN blue chips, the steady-state luminous efficiency of 40 wt%-Al2O3 yellow LED reaches the highest value of 109.49 lm/W, which is 8.54 % higher than that of Al2O3-free sample. Additionally, scattering behavior and conversion efficiency of composite ceramics with different thicknesses were investigated.

Inverse thermal quenching effect in lanthanide-doped upconversion nanocrystals for anti-counterfeiting

2018 ◽  
Vol 6 (20) ◽  
pp. 5427-5433 ◽  
Author(s):  
Lei Lei ◽  
Daqin Chen ◽  
Can Li ◽  
Feng Huang ◽  
Junjie Zhang ◽  
...  
Keyword(s):  
Energy Level ◽  
Thermal Quenching ◽  
Defect State ◽  
Quenching Effect ◽  
High Security ◽  
Upconversion Nanocrystals

An inverse thermal quenching effect is actualized in uniform lanthanide-doped Na3ZrF7 by artificially introducing defect state with an appropriate energy level. These kinds of systems are very suitable for anti-counterfeiting with high security.

Multifunctional NaYF4:Yb3+, Er3+@Au Nanocomposites: Upconversion Luminescence, Temperature Sensing and Photothermal Therapy

2015 ◽  
Vol 1088 ◽  
pp. 23-27 ◽  
Author(s):  
Dong Dong Li ◽  
Qi Yue Shao ◽  
Yan Dong ◽  
Jian Qing Jiang
Keyword(s):  
Gold Nanoparticles ◽  
Photothermal Therapy ◽  
Upconversion Luminescence ◽  
Separation Distance ◽  
Temperature Sensing ◽  
Upconversion Nanoparticles ◽  
Composite Nanostructures ◽  
Sensing Properties ◽  
Quenching Effect ◽  
Biomedical Fields

Composite nanostructures of NaYF4:Yb3+, Er3+@Au have been successfully prepared by attaching gold nanoparticles onto the surface of NaYF4: Yb3+, Er3+ upconversion nanoparticles (UCNPs). NaYF4 inert shell was used to adjust the separation distance between gold nanoparticles and UCNPs. Effects of the gold nanoparticles on their upconversion luminescent (UCL), temperature sensing and photothermal therapy properties were systematically investigated. For all samples, a slight decrease of the UCL intensity was observed after gold nanoparticles attachment, suggesting that the nonradiative quenching effect is the dominant interaction between UCNPs and gold nanoparticles. However, the reduction of the UCL intensity is negligible due to the significant improvement of UCL properties by NaYF4shell. In addition, the gold attachment can obviously improve the photothermal conversion effect, but do not affect the temperature sensing properties of NaYF4:Yb3+, Er3+ UCNPs, indicating their high capability for multifunctional applications in biomedical fields.

Enhancing negative thermal quenching effect via low-valence doping in two-dimensional confined core–shell upconversion nanocrystals

2018 ◽  
Vol 6 (43) ◽  
pp. 11587-11592 ◽  
Author(s):  
Lei Lei ◽  
Jienan Xia ◽  
Yao Cheng ◽  
Yuansheng Wang ◽  
Gongxun Bai ◽  
...  
Keyword(s):  
Emission Intensity ◽  
Thermal Quenching ◽  
Core Shell ◽  
Two Dimensional ◽  
Quenching Effect ◽  
Upconversion Nanocrystals

Doping low-valence ions in core–shell NC is applied to improve negative thermal quenching effect. With the increase in temperature from 293 to 413 K, the UC emission intensity of 20Yb/2Er : NaGdF4 (12 nm) increases by 2.2 times, whereas that of NaGdF4@20Ca/20Yb/2Er: NaGdF4 (11 nm) increases by 10.9 times.

Thermal quenching effect of an infrared deep level in Mg-doped p-type GaN films

2002 ◽  
Vol 80 (10) ◽  
pp. 1767-1769 ◽  
Author(s):  
Keunjoo Kim ◽  
Sang Jo Chung
Keyword(s):  
Deep Level ◽  
Thermal Quenching ◽  
Quenching Effect ◽  
P Type ◽  
Mg Doped

scholarly journals The reduction of the thermal quenching effect in laser-excited phosphor converters using highly thermally conductive hBN particles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Akvilė Zabiliūtė-Karaliūnė ◽  
Justina Aglinskaitė ◽  
Prancis̆kus Vitta
Keyword(s):  
Hexagonal Boron Nitride ◽  
Imaging Techniques ◽  
Thermal Quenching ◽  
Optical Power ◽  
Excitation Power ◽  
Excitation Power Density ◽  
Quenching Effect ◽  
Wide Range ◽  
Thermally Conductive ◽  
Phosphor Thermometry

AbstractPhosphor converters for solid state lighting applications experience a strong thermal stress under high-excitation power densities. The recent interest in laser diode based lighting has made this issue even more severe. This research presents an effective approach to reduce the thermal quenching effect and damage of laser-excited phosphor-silicone converters using thermally conductive hexagonal boron nitride (hBN) particles. Herein, the samples are analyzed by employing phosphor thermometry based on the photoluminescence decay time, and thermo-imaging techniques. The study shows that hBN particle incorporation increases the thermal conductivity of a phosphor-silicone mixture up to 5 times. It turns out, that the addition of hBN to the Eu$$^{2+}$$ 2 + doped chalcogenide-silicone converters can increase the top-limit excitation power density from 60 to 180 W cm$$^{-2}$$ - 2 , thus reaching a 2.5 times higher output. Moreover, it is shown that the presence of hBN in Ce$$^{3+}$$ 3 + activated garnet phosphor converters, may increase the output power by up to 1.8 times and that such converters can withstand 218 W cm$$^{-2}$$ - 2 excitation. Besides, hBN particles are also found to enhance the stability of the converters chromaticity and luminous efficacy of radiation. This means that the addition of hBN particles into silicone-based phosphor converter media is applicable in a wide range of different areas, in particular, the ones requiring a high optical power output density.

A NEW THERMOLUMINESCENCE GENERAL ORDER GLOW CURVE FIT FUNCTION CONSIDERING THERMAL QUENCHING EFFECT

2019 ◽  
Vol 187 (1) ◽  
pp. 103-107
Author(s):  
S Harooni ◽  
M Zahedifar ◽  
E Sadeghi ◽  
Z Ahmadian
Keyword(s):  
Kinetic Parameters ◽  
Glow Curve ◽  
Thermal Quenching ◽  
Glow Peak ◽  
Heating Rates ◽  
Order Model ◽  
Quenching Effect ◽  
Fitting Procedure ◽  
Curve Fit ◽  
General Order

Abstract A new thermoluminescence (TL) general order glow curve fit function in terms of the intensity of peak maximum, Im and the peak temperature, Tm is presented in which thermal quenching (TQ) effect has been taken into account. Also, the conventional general order model and the new presented function were fitted to the glow peak 5 of LiF:Mg,Ti (TLD-100) and the kinetic parameters were obtained for different heating rates as the results of fitting procedure. It was found that increasing the heating rate, which makes the TQ more prominent, causes more divergence between the kinetic parameters extracted by applying two models. Considering that the TL intensity and the glow peak area reduce with shifting the glow peak to higher temperatures as a result of TQ, the new presented function gives more reliable results for the kinetic parameters.

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