Article
Optics
Yun Wang, Jiquan Huang, Yuqing Lin, Zhonghua Deng, Qiufeng Huang, Zhuguang Liu, Jian Chen, Wang Guo
Summary: In this study, cyan-emitting Lu(3)ScAl(4-x)GaxO(12):Ce3+ persistent luminescent ceramics that can be excited by visible-light were fabricated and their photoluminescence and afterglow properties were investigated. The substitution of Ga for Al has three effects on the optical properties of the garnet phosphors: making the emission spectrum blue-shift, deteriorating the luminescence performance, and inducing afterglow. The Lu(2.99)Ce(0.01)ScAl(4-x)GaxO(12) ceramics with Ga content (x) around 2.5 can be efficiently excited by sunlight or indoor/outdoor w-LEDs and produce bright and long-lasting afterglow that matches human scotopic vision well.
JOURNAL OF LUMINESCENCE
(2023)
Article
Materials Science, Ceramics
Runze Li, Huahui Li, Dongyun Zhang, Chengkang Chang
Summary: Redshifted long persistent LiMgxSr4-x-2y(BO3)(3): y Eu2+, Dy3+(Nd3+) phosphors were successfully prepared through a high-temperature solid-state process in a reducing atmosphere. The emission of the phosphors showed redshift characteristics between 633 and 660 nm with an increase in Mg2+ substitution concentration, mainly due to enhanced energy level splitting of Eu2+ after Mg2+ replacement. The afterglow performance of LiMg0.6Sr3.4-2y(BO3)(3): y Eu2+, Dy3+ (Nd3+) samples improved with increasing concentrations of the doped rare-earth ions. An optimal concentration of 6% achieved the best afterglow performance, attributed to the development of high concentration traps with suitable energy levels, as confirmed by afterglow measurements and thermoluminescence tests. The Nd3+ codoped phosphor displayed improved afterglow performance compared to the Dy3+ codoped phosphor at the same doping concentration, due to the ability of Nd3+ to easily incorporate into the borate lattice and generate electron traps with high concentrations.
CERAMICS INTERNATIONAL
(2023)
Article
Instruments & Instrumentation
L. Tafoya, V. Geppert-Kleinrath, E. Smith, K. McClellan, K. Pestovich, C. Richards, B. Wiggins
Summary: Scintillators are crucial for nuclear instrumentation and its applications, such as plasma diagnostics and imaging. The radiation tolerance of scintillator materials is important as the yields in controlled fusion experiments increase. This study investigates the effects of radiation damage on Ce-doped mixed garnet ceramics and determines the optimal cerium dopant concentration for Y2LuAl5O12.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Physics, Multidisciplinary
V Stasiv, M. Glowacki, J. Fink-Finowicki, Ya Zhydachevskyy, S. Ubizskii, M. Berkowski, A. Suchocki
Summary: This work presents an experimental study comparing the growth of (Y, Gd)AlO3:Mn2+ crystals using the Czochralski method in inert gas atmosphere and the floating-zone method in ambient air. The study also analyzes the Mn2+/Mn4+ ratio and the energy depth of dosimetric and shallow traps in comparison to YAlO3:Mn2+ and (Y, Lu)AlO3:Mn2+ crystals studied before.
ACTA PHYSICA POLONICA A
(2022)
Article
Optics
Vitalii Boiko, Zhengfa Dai, Jiang Li, Dariusz Hreniak
Summary: The influence of Nd concentration on the photoluminescence and persistent luminescence properties of (Y,Ce,Nd)(3)(Al,Cr)(2)Ga3O12 ceramics was studied, and the depth of traps depending on Nd concentration was analyzed.
JOURNAL OF LUMINESCENCE
(2022)
Article
Optics
M. Korzhik, P. Karpyuk, A. Bondarau, A. Ilyushin, I. Kamenskikh, D. Lelekova, V. Pustovarov, V. Retivov, V. Smyslova, D. Tavrunov, A. Vasil'ev
Summary: The crystalline ceramic material (Gd, Y)(3)Al2Ga3O12 codoped with Ce and Tb (GYAGG: Ce, Tb) has been proven to be a high light yield scintillator, making it suitable for detectors operating in a current measurement mode and as high-flux sources of optical photons under ionizing radiation of different types.
JOURNAL OF LUMINESCENCE
(2024)
Article
Chemistry, Physical
J. Barta, K. S. Pestovich, J. A. Valdez, B. W. Wiggins, C. Richards, E. Smith, J. H. Clayton, D. Smalley, K. J. McClellan
Summary: Quenching from the melt using an Optical Floating Zone furnace was studied as a high-throughput preparation method for screening novel scintillating materials. Polycrystalline rare-earth aluminum garnets and yttrium gallium aluminum garnets were synthesized and characterized, with Y3Al5O12, LuY2Al5O12, and GdY2Al5O12 identified as having the highest scintillation efficiency among the prepared samples.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Instruments & Instrumentation
Edgar van Loef, Urmila Shirwadkar, Lakshmi Soundara Pandian, Guido Ciampi, Luis Stand, Mao-Hua Du, Merry Koschan, Matthew Loyd, Mariya Zhuravleva, Charles Melcher, Kanai Shah
Summary: This paper investigates the crystal growth, DFT calculations, and scintillation properties of Tl(3)LnCl(6) and TlLn(2)Cl(7) (Ln = Y, Gd) crystals. These crystals belong to the Nesohalides and Phyllohalides families with varying crystal structures, and exhibit light yields typically in the range of 35,000-40,000 ph/MeV.
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
(2021)
Article
Materials Science, Ceramics
Chuchu Ma, Mengyao Wang, Bowen Xue, Bin Lu
Summary: A novel garnet phosphor was synthesized using a chemical coprecipitation method and controlled for luminescent properties through different doping and thermal treatment conditions. Co-doping with Ce3+ and Cr3+ resulted in specific spectral characteristics for the phosphor.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
N. V. Vasil'eva, D. A. Spassky, S. Omelkov, V. G. Plotnichenko, D. A. Vasil'ev
Summary: (Pb,Gd)(3)(Al,Ga)(5)O-12:Ce3+,Eu3+ films were grown by liquid-phase epitaxy and their luminescence properties were studied. The results demonstrated energy transfer from Ce3+ to Eu3+, leading to quenching of Ce3+ luminescence.
INORGANIC MATERIALS
(2022)
Article
Optics
Vasilii Khanin, Ivan Venevtsev, Kirill Chernenko, Vladimir Pankratov, Konstantin Klementiev, Thomas van Swieten, Arnoldus J. van Bunningen, Ivan Vrubel, Roman Shendrik, Cees Ronda, Piotr Rodnyi, Andries Meijerink
Summary: The oxidation state of Ce ions in garnets affects their luminescence efficiency, with too high Ce4+ concentration leading to decreased performance. The energy conversion processes between Ce3+ and Ce4+ are crucial in determining the luminescence performance of the garnets.
JOURNAL OF LUMINESCENCE
(2021)
Article
Chemistry, Physical
Yaroslav Zhydachevskyy, Yuriy Hizhnyi, Sergii G. Nedilko, Irina Kudryavtseva, Vladimir Pankratov, Vasyl Stasiv, Leonid Vasylechko, Dmytro Sugak, Aleksandr Lushchik, Marek Berkowski, Andrzej Suchocki, Nickolai Klyui
Summary: The study found that band gap engineering can be achieved in RAlO3 (R = Y, Gd, La) perovskites by reducing the trap depths of intrinsic point defects and identifying specific trapping centers. Experimental and theoretical approaches demonstrated the feasibility of this process.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Xiangyun Zhao, Yining Pan, Wangxian Chen, Wentong Yang, Qiang Zeng, Linhong Li, Xiang Liao, Zongliang Zhang, Siliang Liu, Yanqing Lai, Fangyang Liu
Summary: Suppressing band tailing and nonradiative recombination is crucial for improving CZTSSe thin film solar cell performance. Cation substitution, such as Ag substitution for Cu, is commonly used to address these issues. This study investigates the effectiveness and mechanism of Ga doping using different approaches. Chemical-based Ga doping can lower defect activation energy and suppress nonradiative recombination, achieving a power conversion efficiency of 12.12% with a V-oc of 522 mV at 2% Ga doping.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Materials Science, Ceramics
Yuting Zhang, Huan Tu, Guoying Zhao, Jingshan Hou, Yufeng Liu, Xin Qiao, Zhongzhi Wang, Bo Li, Ji-Guang Li, Feng Wang, Yongzheng Fang
Summary: Compared with other fluorescent crystal phases, garnet has better structural stability in a glass matrix and enables precise control of emissions. In this study, the coordination field of Ce3+ ion was regulated through co-substitution, resulting in spectrum regulation in the yellow-green range. By using Ba2+-Si4+ cations to replace Y3+-Al3+ cations, the emission peak of the garnet phosphor was blue-shifted from 552 to 539 nm. The fluorescent films prepared using a low-temperature co-sintering process showed less erosion and even dispersion of the fluorescence crystals in the glass matrix. The warm white film prepared has potential application value in the whole spectra field.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Karol Bartosiewicz, Verena Fritz, David van der Heggen, Damian Szymanski, Justyna Zeler, Jan Pejchal, Akihiro Yamaji, Romana Kucerkova, Alena Beitlerova, Shunsuke Kurosawa, Akira Yoshikawa, Philippe F. Smet, Eugeniusz Zych, Martin Nikl
Summary: This research investigates the principles of crystal chemistry related to incorporating incompatible atoms into a garnet host lattice, which can guide the design of new garnet compounds with novel properties. The inclusion of incompatible La atoms in the Lu3Al2Ga3O12:Ce host lattice is used as a research model, demonstrating the potential for designing material properties through atom mismatches in a crystal lattice.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Yingze Zhu, Xuesong Wang, Jianwei Qiao, Maxim S. Molokeev, Hendrik C. Swart, Lixin Ning, Zhiguo Xia
Summary: To promote the development of NIR light sources, the researchers discovered a novel Eu2+-activated broadband NIR-emitting phosphor and investigated its design principles and mechanism using density functional theory calculations. The results showed that with an increase in the Ba/Sr atomic ratio, the emission band of Eu2+ red-shifted and the FWHM enlarged. The application of NIR phosphor-converted LEDs was demonstrated, indicating their potential in night-vision technology.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Analytical
K. Shingange, G. H. Mhlongo, H. C. Swart
Summary: In this study, a nanofiber network of La1_ xCexCoO3 was prepared and the X-ray diffraction analysis revealed the appearance of CeO2 with increasing Ce-substitution. The gas sensing measurements showed that the combination of nanofiber morphology and the catalytic effect of Ce resulted in enhanced ethanol sensing performance, especially for the La0.8Ce0.2CoO3 sample. The particle-interconnected nanofiber morphology allowed for greater resistance changes and the Ce-substitution increased the surface oxygen defects, promoting a more advanced gas and surface interaction. This research demonstrates the potential ethanol sensing capabilities induced by Ce-partial substitution on the La-site.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Chemistry, Analytical
Murendeni I. Nemufulwi, Hendrik C. Swart, Katekani Shingange
Summary: Heterojunction interfaces between metal-oxides can significantly improve gas sensing through charge distribution caused by lattice mismatch. This study focuses on the positive synergistic effects of ZnO/ZnFe2O4 heterostructure, which exhibited the best sensing performance among pure ZnO and ZnFe2O4. The enhanced sensing properties were attributed to the higher concentration of oxygen vacancies at the ZnO/ZnFe2O4 interface and enhanced catalytic activity.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Engineering, Electrical & Electronic
Mubarak Y. A. Yagoub, Hendrik C. C. Swart, Elizabeth Coetsee
Summary: A series of CaF2 nanomaterials doped with Y3+ ions under EDTA were synthesized using the hydrothermal method. The results showed the formation of a mixture of cubic CaF2 and [CaY]F-2 phases with increasing Y3+ ion concentration. The particle size and morphology depended on the Y3+ concentration, and EDTA produced a spherical morphology. XPS-HAXPES analysis demonstrated the presence of surface impurities and differences in chemical composition between the surface and subsurface regions.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
(2023)
Article
Materials Science, Multidisciplinary
N. A. M. Saeed, E. Coetsee, H. C. Swart
Summary: The tunability of holmium (Ho3+) emission was achieved by co-doping bismuth (Bi3+) with an yttrium oxyfluoride (YOF) host for optoelectronic applications. The samples were synthesized using the pyrolysis technique followed by annealing in ambient air at 900 degrees C. The co-doped samples exhibited emission components of Bi3+, Bi2+, and Ho3+, with the cathodoluminescence (CL) emission tunable from green to yellow and to orange.
MATERIALS RESEARCH BULLETIN
(2023)
Article
Materials Science, Multidisciplinary
N. J. Shivaramu, B. N. Lakshminarasappa, E. Coetsee, R. E. Kroon, H. C. Swart
Summary: Solution combustion synthesis was used to create undoped and trivalent neodymium doped Y2O3 for potential gamma ray dosimetry and near-infrared laser material applications. X-ray powder diffraction analysis showed that the materials had a cubic Y2O3 single phase structure up to a dopant level of 2 mol%. Higher dopant concentrations resulted in the existence of a Nd2O3 solid solution. The nanocrystals were characterized by X-ray photoelectron spectroscopy, confirming excellent stoichiometric control. The gamma-ray irradiated phosphors exhibited a thermoluminescence peak at about 394K that increased in intensity up to 7 kGy and then decreased. The Nd3+ doped Y2O3 sample exposed to 60Co gamma-rays showed peaks at 395, 445, 496, and 596K, attributed to the F, F+, and V-centers.
MATERIALS RESEARCH BULLETIN
(2023)
Article
Nanoscience & Nanotechnology
Krishnan Rajagopalan, Eduard Madirov, Dmitry Busko, Ian A. Howard, Bryce S. Richards, Hendrik C. Swart, Andrey Turshatov
Summary: To achieve more complete recycling of plastic waste, the development of new technologies beyond the state-of-the-art is necessary. Tracer-based sorting, which utilizes the luminescence of special tracers, can enable the identification and separation of different types of plastics based on their reflectance and luminescence spectra.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Ceramics
Sumedha Tamboli, Govind B. Nair, Zhiguo Xia, S. J. Dhoble, H. C. Swart
Summary: In this study, luminescence thermometers based on Pr3+ emissions in the red and NIR regions were used to develop highly sensitive optical thermometer probes. LaOF:Pr3+ nanorods were synthesized and exhibited excellent photoluminescence emission. The nanorods showed temperature-dependent photoluminescence, which was exploited for thermal sensing applications. The results demonstrate the promising potential of these nanorods for nanothermometry applications due to their high thermal sensitivity and stability.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Yu Chen, Zhiyu Yang, Jiance Jin, Jianwei Qiao, Yuzhen Wang, Maxim S. Molokeev, Hendrik C. Swart, Zhiguo Xia
Summary: Exploring oxide-based red-emitting phosphors is important for improving the color rendering index and reducing the correlated color temperature of white-light-emitting diode (LED) lighting sources. This study synthesized a red-emitting Sr2LaGaO5:Eu2+ oxide phosphor and successfully achieved tunable emission by substituting Sr with Ba atoms. By mixing different colored phosphors, a white LED device with high color rendering index and low color-dependent temperature was fabricated.
CHEMISTRY OF MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Babiker M. Jaffar, H. C. Swart, H. A. A. Seed Ahmed, A. Yousif, R. E. Kroon, O. M. Ntwaeaborwa
Summary: Bi3+ doped LaGaO3 powders and thin films were prepared by citric acid sol-gel combustion method and pulsed laser deposition (PLD) technique. The highest photoluminescence (PL) and cathodoluminescence (CL) emissions were observed from La1-x GaO3:Bi3+ powders annealed at the appropriate temperature.
Article
Crystallography
Vhahangwele Makumbane, Mubarak Y. A. Yagoub, Zhiguo Xia, Robin E. Kroon, Hendrik C. Swart
Summary: The up-conversion (UC) and temperature sensing properties of Y2O3:Ho3+, Yb3+ phosphors were investigated. The Y2O3:Ho3+, Yb3+ phosphors were synthesized using a solution combustion method and their cubic crystal structure was confirmed by X-ray powder diffraction. Scanning electron microscopy was used to study the surface morphologies of the UC phosphors. Under 980 nm excitation, the UC emissions of Ho3+ were observed, which occurred through UC energy transfer (ET) processes. The sensing behavior of the phosphor was studied through the green to red fluorescence intensity ratio (FIR) and the maximum absolute sensitivity and relative sensitivity values were obtained. The results indicate that the prepared Y2O3:Ho3+, Yb3+ phosphor is suitable for optical sensing at high temperatures.
Article
Materials Science, Multidisciplinary
Sunday A. Ogundipe, Ceboliyazakha L. Ndlangamandla, Mmantsae M. Diale, Mudalo Jozela, Hendrik C. Swart, David E. Motaung, Steven S. Nkosi
Summary: The presence of high concentrations of flammable gases and volatile organic compounds in the atmosphere has adverse effects on human survival. Researchers have prepared double-substitution spinel using the glycol-thermal technique and tested its gas sensing performance towards LPG, ammonia, ethanol, and propanol.
Article
Physics, Condensed Matter
Osama K. M. Bashiar, R. E. Kroon, H. C. Swart, R. A. Harris
Summary: ZnO thin films with near-infrared emission were successfully fabricated using pulsed laser deposition under vacuum conditions, without the need for additional gases or implantation methods. The NIR emission was hypothesized to be caused by defects in the ZnO film due to high energy particle impacts on the sample surface.
PHYSICA B-CONDENSED MATTER
(2024)
Article
Chemistry, Physical
Thabang J. Theka, Boiketlo R. J. Thamaga, Zamaswazi P. Tshabalala, Rapelang G. Motsoeneng, Hendrik C. Swart, David E. Motaung
Summary: In this study, low-concentration benzene detection was achieved by loading Fe3+ on the surface of Co3O4/TiO2, and low detection limits were provided. The heterostructure-based sensor exhibited good stability and high response to benzene.
APPLIED SURFACE SCIENCE
(2024)
Article
Materials Science, Multidisciplinary
Sumedha Tamboli, Govind B. Nair, Ashwini K. Sharma, S. J. Dhoble, H. C. Swart
Summary: Luminescence thermometry is a unique tool for remote temperature sensing, which exploits the variations in the luminescence properties of the probe. Thermometry based on fluorescence intensity ratios (FIR) is widely used due to its self-referenced measure. A study discovered LaOF:Yb3+,Tm3+ upconversion nanoparticles that exhibit blue and near-infrared upconversion photoluminescence under 980 nm laser excitation, making them suitable for temperature sensing.
MATERIALS RESEARCH BULLETIN
(2024)
