This study investigates the thermoluminescence of beta-irradiated natural milky quartz from Minas Gerais, Brazil. Its glow curve, measured at 1 °C/s up to 500 °C, consists of a prominent peak at 85 °C, and four other secondary peaks at 132, 218, 302 and 393 °C. The main peak, selected for detailed analysis due to its ubiquity in various quartz types, reproducibility, and stable kinetic parameters, shows a sublinear dose-response up to 35 Gy. Kinetic analysis shows that the peak follows first-order kinetics, has an activation energy of 0.85 eV, and a frequency factor of the order of 1011 s−1. The main glow peak is also affected by thermal quenching with an activation energy of 0.8 eV. Beyond conventional dosimetry, this study highlights the scientific significance of this peak through detailed kinetic analysis providing insight into luminescence behaviour in quartz.
{"title":"Kinetic analysis of thermoluminescence of Brazilian milky quartz","authors":"Sunil Thomas , N.M. Trindade , I.A. Ferreira , M.L. Chithambo","doi":"10.1016/j.jlumin.2025.121701","DOIUrl":"10.1016/j.jlumin.2025.121701","url":null,"abstract":"<div><div>This study investigates the thermoluminescence of beta-irradiated natural milky quartz from Minas Gerais, Brazil. Its glow curve, measured at 1 °C/s up to 500 °C, consists of a prominent peak at 85 °C, and four other secondary peaks at 132, 218, 302 and 393 °C. The main peak, selected for detailed analysis due to its ubiquity in various quartz types, reproducibility, and stable kinetic parameters, shows a sublinear dose-response up to 35 Gy. Kinetic analysis shows that the peak follows first-order kinetics, has an activation energy of 0.85 eV, and a frequency factor of the order of 10<sup>11</sup> s<sup>−1</sup>. The main glow peak is also affected by thermal quenching with an activation energy of 0.8 eV. Beyond conventional dosimetry, this study highlights the scientific significance of this peak through detailed kinetic analysis providing insight into luminescence behaviour in quartz.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121701"},"PeriodicalIF":3.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of full-spectrum white LEDs is significantly hindered by the “cyan gap” in the 470–510 nm spectral region. Addressing this gap with moderate -quality cyan-emitting phosphors, efficiently excited by violet LED chips, is crucial for achieving high color rendering index (Ra >90) illumination. In this study, a novel and moderate efficient garnet-structured cyan-emitting phosphor Ca2LuZr2Al1.5Ga1.5O12:Ce3+ (CLZAGO:Ce3+) was effectively prepared via a high-temperature solid-state reaction route. When excited at 410 nm, the optimized CLZAGO:0.04Ce3+ sample displays a robust cyan emission peaking at 484 nm, accompanied by a broad emission band spanning 420–650 nm and a full width at half-maximum (FWHM) of 90 nm, which efficiently fills the cyan gap commonly observed in conventional White light-emitting diodes (WLEDs). The phosphor exhibits available thermal stability, preserving 53 % of its room-temperature emission intensity at 423 K, and achieves a moderate external quantum efficiency (EQE) of 45.43 %. Finally, when CLZAGO:Ce3+ was combined with commercial blue-emitting Sr5(PO4)3Cl:Eu2+ (SPOC:Eu2+), green-emitting (Ba, Sr)2SiO4:Eu2+ (BSSO:Eu2+), and red-emitting CaAlSiN3:Eu2+ (CASN:Eu2+) phosphors and integrated into a 410 nm violet LED chip, a full-spectrum WLED with an enhanced Ra of 95 was achieved. These findings underscore the critical role of CLZAGO:Ce3+ as a promising cyan-emitting component for next-generation high color-rendering full-spectrum WLEDs.
{"title":"A novel cyan-emitting Ca2LuZr2Al1.5Ga1.5O12:Ce3+ phosphor excited by violet light toward full-spectrum white LEDs","authors":"Yingchun Ge, Tao Wu, Langping Dong, Zhiyu Qin, Jianghua Wu, Guangxiang Jiang, Guoying Zhao, Shuai Yang, Jingshan Hou, Yongzheng Fang","doi":"10.1016/j.jlumin.2025.121714","DOIUrl":"10.1016/j.jlumin.2025.121714","url":null,"abstract":"<div><div>The development of full-spectrum white LEDs is significantly hindered by the “cyan gap” in the 470–510 nm spectral region. Addressing this gap with moderate -quality cyan-emitting phosphors, efficiently excited by violet LED chips, is crucial for achieving high color rendering index (Ra >90) illumination. In this study, a novel and moderate efficient garnet-structured cyan-emitting phosphor Ca<sub>2</sub>LuZr<sub>2</sub>Al<sub>1.5</sub>Ga<sub>1.5</sub>O<sub>12</sub>:Ce<sup>3+</sup> (CLZAGO:Ce<sup>3+</sup>) was effectively prepared via a high-temperature solid-state reaction route. When excited at 410 nm, the optimized CLZAGO:0.04Ce<sup>3+</sup> sample displays a robust cyan emission peaking at 484 nm, accompanied by a broad emission band spanning 420–650 nm and a full width at half-maximum (FWHM) of 90 nm, which efficiently fills the cyan gap commonly observed in conventional White light-emitting diodes (WLEDs). The phosphor exhibits available thermal stability, preserving 53 % of its room-temperature emission intensity at 423 K, and achieves a moderate external quantum efficiency (EQE) of 45.43 %. Finally, when CLZAGO:Ce<sup>3+</sup> was combined with commercial blue-emitting Sr<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>Cl:Eu<sup>2+</sup> (SPOC:Eu<sup>2+</sup>), green-emitting (Ba, Sr)<sub>2</sub>SiO<sub>4</sub>:Eu<sup>2+</sup> (BSSO:Eu<sup>2+</sup>), and red-emitting CaAlSiN<sub>3</sub>:Eu<sup>2+</sup> (CASN:Eu<sup>2+</sup>) phosphors and integrated into a 410 nm violet LED chip, a full-spectrum WLED with an enhanced Ra of 95 was achieved. These findings underscore the critical role of CLZAGO:Ce<sup>3+</sup> as a promising cyan-emitting component for next-generation high color-rendering full-spectrum WLEDs.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121714"},"PeriodicalIF":3.6,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1016/j.jlumin.2025.121703
Duo Chen, Ruiyuan Bi, Lifeng Xun, Xiaopeng Zhao
Building upon an anion doping strategy, this study proposes using F− regulation to enhance the luminescence performance of Ga2O3:Eu3+ phosphors. To address the contradiction between the low Eu3+ characteristic absorption and the strong Ga2O3 intrinsic emission induced by charge transfer band (CTB) excitation in traditional Ga2O3:Eu3+ systems, this study successfully prepared a series of Ga2O3:Eu3+/F− phosphors with different F− doping concentrations using an oleic acid-assisted solvothermal method combined with high-temperature sintering. The phases, morphology, structure, and luminescent properties of the samples were systematically analyzed. Experimental results show that F− successfully replaces part of the O2− in the phosphor and alters the local symmetry of Eu3+, which results in 5D0→7F1 becoming the main transition path for the characteristic luminescence of Eu3+, shifting the main emission peak from 615 nm to 587 nm. Under CTB excitation, F− doping significantly enhanced the Eu3+ characteristic emission without significantly altering the Ga2O3 matrix emission. Under optimal reaction conditions, the luminescence intensity of the magnetic dipole transition in Ga2O3:Eu3+/F− phosphor was enhanced approximately 26-fold, with the quantum yield reaching 9.26 % and the 5D0 excited state lifetime increasing to 1.83 ms. This modulation of the emission behavior also caused the phosphor chromaticity to shift from blue-purple to orange. This study demonstrates the selective enhancement mechanism of F− doping in Ga2O3:Eu3+ luminescence, providing a reference for the design of high-performance rare-earth luminescent materials.
{"title":"A significant enhancement in the luminescent properties of Ga2O3:Eu3+ phosphors induced by fluorine-doping","authors":"Duo Chen, Ruiyuan Bi, Lifeng Xun, Xiaopeng Zhao","doi":"10.1016/j.jlumin.2025.121703","DOIUrl":"10.1016/j.jlumin.2025.121703","url":null,"abstract":"<div><div>Building upon an anion doping strategy, this study proposes using F<sup>−</sup> regulation to enhance the luminescence performance of Ga<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup> phosphors. To address the contradiction between the low Eu<sup>3+</sup> characteristic absorption and the strong Ga<sub>2</sub>O<sub>3</sub> intrinsic emission induced by charge transfer band (CTB) excitation in traditional Ga<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup> systems, this study successfully prepared a series of Ga<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup>/F<sup>−</sup> phosphors with different F<sup>−</sup> doping concentrations using an oleic acid-assisted solvothermal method combined with high-temperature sintering. The phases, morphology, structure, and luminescent properties of the samples were systematically analyzed. Experimental results show that F<sup>−</sup> successfully replaces part of the O<sup>2−</sup> in the phosphor and alters the local symmetry of Eu<sup>3+</sup>, which results in <sup>5</sup>D<sub>0</sub>→<sup>7</sup>F<sub>1</sub> becoming the main transition path for the characteristic luminescence of Eu<sup>3+</sup>, shifting the main emission peak from 615 nm to 587 nm. Under CTB excitation, F<sup>−</sup> doping significantly enhanced the Eu<sup>3+</sup> characteristic emission without significantly altering the Ga<sub>2</sub>O<sub>3</sub> matrix emission. Under optimal reaction conditions, the luminescence intensity of the magnetic dipole transition in Ga<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup>/F<sup>−</sup> phosphor was enhanced approximately 26-fold, with the quantum yield reaching 9.26 % and the <sup>5</sup>D<sub>0</sub> excited state lifetime increasing to 1.83 ms. This modulation of the emission behavior also caused the phosphor chromaticity to shift from blue-purple to orange. This study demonstrates the selective enhancement mechanism of F<sup>−</sup> doping in Ga<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup> luminescence, providing a reference for the design of high-performance rare-earth luminescent materials.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121703"},"PeriodicalIF":3.6,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-15DOI: 10.1016/j.jlumin.2025.121702
Zichun Zhou, Chen Ming, Yi-Yang Sun
The development of novel violet-light-excitable phosphors for next-generation white light-emitting diodes (WLEDs) is often limited by the high computational cost of lanthanide excited-state calculations and the low efficiency of traditional discovery methods. Here, we introduce a data-driven framework based on graph neural networks (GNNs) to accelerate this discovery process. By integrating large language models with data-mining techniques, we constructed a comprehensive database of 822 experimentally verified phosphors (455 Eu2+ doped and 367 Ce3+ doped). A systematic benchmark of three GNN architectures (CGCNN, MEGNet, and GATGNN) revealed that the GATGNN model exhibited optimal performance for the Eu2+ system, achieving a mean absolute error (MAE) of 0.18 eV in emission energy prediction and an area under the ROC curve (AUC) of 0.85 for classifying violet-light-excitable materials. Leveraging this model, we performed a high-throughput screening of 12,558 candidates, resulting in the prediction of 68 novel violet-light-excitable phosphors. This work not only provides an efficient tool to address the blue-light hazard and color-rendering bottlenecks in current WLEDs, but also showcases the power of AI-driven paradigms in accelerating the discovery of functional materials.
{"title":"High-throughput screening of violet-light-excitable phosphors driven by graph neural network","authors":"Zichun Zhou, Chen Ming, Yi-Yang Sun","doi":"10.1016/j.jlumin.2025.121702","DOIUrl":"10.1016/j.jlumin.2025.121702","url":null,"abstract":"<div><div>The development of novel violet-light-excitable phosphors for next-generation white light-emitting diodes (WLEDs) is often limited by the high computational cost of lanthanide excited-state calculations and the low efficiency of traditional discovery methods. Here, we introduce a data-driven framework based on graph neural networks (GNNs) to accelerate this discovery process. By integrating large language models with data-mining techniques, we constructed a comprehensive database of 822 experimentally verified phosphors (455 Eu<sup>2+</sup> doped and 367 Ce<sup>3+</sup> doped). A systematic benchmark of three GNN architectures (CGCNN, MEGNet, and GATGNN) revealed that the GATGNN model exhibited optimal performance for the Eu<sup>2+</sup> system, achieving a mean absolute error (MAE) of 0.18 eV in emission energy prediction and an area under the ROC curve (AUC) of 0.85 for classifying violet-light-excitable materials. Leveraging this model, we performed a high-throughput screening of 12,558 candidates, resulting in the prediction of 68 novel violet-light-excitable phosphors. This work not only provides an efficient tool to address the blue-light hazard and color-rendering bottlenecks in current WLEDs, but also showcases the power of AI-driven paradigms in accelerating the discovery of functional materials.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121702"},"PeriodicalIF":3.6,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-12DOI: 10.1016/j.jlumin.2025.121699
Lucca Blois , Ricardo L. Longo , Albano N. Carneiro Neto , Wagner M. Faustino , Renaldo T. Moura Jr. , Maria C.F.C. Felinto , Hermi F. Brito , Oscar L. Malta
A derivation of the equations in the Judd-Ofelt theory for quantifying the intensities of 4f-4f transitions based on the second quantization or occupation number representation is presented. This derivation is more concise and compact, emphasizing some approximations employed and aims at simplifying the comprehension of the theory. It is almost self-contained, with the properties and relationships pertaining to the second quantization approach being introduced, and it requires some basic understanding of quantum mechanics, particularly, of angular momentum techniques (e.g. 3-j symbols and Racah operators). It is expected that this derivation can be followed and comprehended by students, researchers, and enthusiasts, hopefully encouraging new implementations, applications, and developments involving the intensities of 4f-4f transitions.
{"title":"A derivation of Judd-Ofelt theory by second quantization of configuration interaction","authors":"Lucca Blois , Ricardo L. Longo , Albano N. Carneiro Neto , Wagner M. Faustino , Renaldo T. Moura Jr. , Maria C.F.C. Felinto , Hermi F. Brito , Oscar L. Malta","doi":"10.1016/j.jlumin.2025.121699","DOIUrl":"10.1016/j.jlumin.2025.121699","url":null,"abstract":"<div><div>A derivation of the equations in the Judd-Ofelt theory for quantifying the intensities of 4f-4f transitions based on the second quantization or occupation number representation is presented. This derivation is more concise and compact, emphasizing some approximations employed and aims at simplifying the comprehension of the theory. It is almost self-contained, with the properties and relationships pertaining to the second quantization approach being introduced, and it requires some basic understanding of quantum mechanics, particularly, of angular momentum techniques (e.g. 3-j symbols and Racah operators). It is expected that this derivation can be followed and comprehended by students, researchers, and enthusiasts, hopefully encouraging new implementations, applications, and developments involving the intensities of 4f-4f transitions.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121699"},"PeriodicalIF":3.6,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-12DOI: 10.1016/j.jlumin.2025.121695
Fatemeh Maleki , Nadiya Hadidi , Mehdi Parandin
Tryptophan-derived carbon dots (Try-CDs) were synthesized via a green hydrothermal method and evaluated as a dual-functional nanoplatform for controlled curcumin delivery and fluorescence monitoring. Structural and optical properties were characterized using TEM, DLS, zeta potential, FT-IR, UV–Vis, and PL, with stability confirmed across pH 4–9 and up to 1 M NaCl. Try-CDs exhibited strong blue emission at 438 nm (λex = 360 nm). Curcumin encapsulation improved the zeta potential from −17.8 to −23.3 mV, enhancing colloidal stability while enabling pH-dependent release, accelerated under acidic conditions. Fluorescence intensity decreased linearly with curcumin concentration from 0 to 250 μM (LOD = 0.245 μM), enabling real-time monitoring. DFT and TD-DFT analyses revealed photo-induced charge transfer (PCT) and stable non-covalent interactions in Try-CD–curcumin complexes. These findings demonstrate Try-CDs as biocompatible, self-reporting nanocarriers with significant potential for bioimaging-guided drug delivery and theranostic applications.
{"title":"Dual-functional carbon dots: A fluorescent platform for controlled curcumin delivery and monitoring","authors":"Fatemeh Maleki , Nadiya Hadidi , Mehdi Parandin","doi":"10.1016/j.jlumin.2025.121695","DOIUrl":"10.1016/j.jlumin.2025.121695","url":null,"abstract":"<div><div>Tryptophan-derived carbon dots (Try-CDs) were synthesized via a green hydrothermal method and evaluated as a dual-functional nanoplatform for controlled curcumin delivery and fluorescence monitoring. Structural and optical properties were characterized using TEM, DLS, zeta potential, FT-IR, UV–Vis, and PL, with stability confirmed across pH 4–9 and up to 1 M NaCl. Try-CDs exhibited strong blue emission at 438 nm (λ<sub>ex</sub> = 360 nm). Curcumin encapsulation improved the zeta potential from −17.8 to −23.3 mV, enhancing colloidal stability while enabling pH-dependent release, accelerated under acidic conditions. Fluorescence intensity decreased linearly with curcumin concentration from 0 to 250 μM (LOD = 0.245 μM), enabling real-time monitoring. DFT and TD-DFT analyses revealed photo-induced charge transfer (PCT) and stable non-covalent interactions in Try-CD–curcumin complexes. These findings demonstrate Try-CDs as biocompatible, self-reporting nanocarriers with significant potential for bioimaging-guided drug delivery and theranostic applications.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121695"},"PeriodicalIF":3.6,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145765985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.jlumin.2025.121698
Zebin Wang , Guyot Yannick , Chong Xu , Jian Liu , Xiaodong Xu , Kheirreddine Lebbou , Jun Xu
Nd:LuxY3-xAl5O12 (x = 0, 1, 1.5, 2, 3) crystal fibers doped with 0.2 at.% Nd3+ were successfully grown using the laser-heated pedestal growth (LHPG) method. The effects of the Lu3+/Y3+ ratio on the structural, absorption, and emission properties were systematically studied. Absorption spectra show that Nd:LuxY3-xAl5O12 (Nd:LuYAG) crystal fibers combine the high absorption cross section of Nd:YAG and the broad absorption bandwidth of Nd:LuAG. Judd-Ofelt analysis was employed to evaluate the optical transition parameters. Under 808 nm excitation, the fluorescence lifetime of the 4F3/2 level gradually decreased with increasing Lu3+ content. These results indicate that adjusting the Lu3+/Y3+ ratio in Nd:LuYAG crystal fibers allows optimization for high-performance laser applications, presenting a potential alternative to conventional Nd:YAG gain media.
{"title":"Spectroscopic properties of LHPG-grown Nd:LuxY3-xAl5O12 single crystal fibers","authors":"Zebin Wang , Guyot Yannick , Chong Xu , Jian Liu , Xiaodong Xu , Kheirreddine Lebbou , Jun Xu","doi":"10.1016/j.jlumin.2025.121698","DOIUrl":"10.1016/j.jlumin.2025.121698","url":null,"abstract":"<div><div>Nd:Lu<sub>x</sub>Y<sub>3-x</sub>Al<sub>5</sub>O<sub>12</sub> (x = 0, 1, 1.5, 2, 3) crystal fibers doped with 0.2 at.% Nd<sup>3+</sup> were successfully grown using the laser-heated pedestal growth (LHPG) method. The effects of the Lu<sup>3+</sup>/Y<sup>3+</sup> ratio on the structural, absorption, and emission properties were systematically studied. Absorption spectra show that Nd:Lu<sub>x</sub>Y<sub>3-x</sub>Al<sub>5</sub>O<sub>12</sub> (Nd:LuYAG) crystal fibers combine the high absorption cross section of Nd:YAG and the broad absorption bandwidth of Nd:LuAG. Judd-Ofelt analysis was employed to evaluate the optical transition parameters. Under 808 nm excitation, the fluorescence lifetime of the <sup>4</sup>F<sub>3/2</sub> level gradually decreased with increasing Lu<sup>3+</sup> content. These results indicate that adjusting the Lu<sup>3+</sup>/Y<sup>3+</sup> ratio in Nd:LuYAG crystal fibers allows optimization for high-performance laser applications, presenting a potential alternative to conventional Nd:YAG gain media.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"290 ","pages":"Article 121698"},"PeriodicalIF":3.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.jlumin.2025.121697
Yiqi Yu , Liming Zhang , Liuzhen Feng , Renfu Li , Zhiwen Ao , Jinmin Zhang , Ying Yang , Jinsheng Liao
Cr3+-doped deep-red phosphors are ideal for plant growth lighting, yet achieving high thermal stability in tungstate hosts remains challenging. This study demonstrates that co-doping Al3+ and Cr3+ into the negative thermal expansion (NTE) material Sc2(WO4)3 effectively strengthens the crystal field, leading to an intensified narrow-band deep-red emission from Cr3+. A series of Sc1.6Al0.4W3O12: Cr3+ deep-red phosphors were successfully synthesized via solid-state reaction. The optimized Sc1.6Al0.4W3O12:0.25 %Cr3+ phosphor exhibits 2E → 4A2 emission of Cr3+ at 696 nm under 406 nm excitation, matching the PFR phytochrome absorption. It retains 61.9 % of its room temperature (RT) luminescence intensity at 423 K, demonstrating superior thermal stability over analogues. The fabricated deep-red pc-LED, with its emission peak perfectly aligned with PFR, confirms its potential for plant growth lighting.
{"title":"Synthesis and luminescence properties of deep-red-emitting Sc1.6Al0.4W3O12: Cr3+ phosphor for plant growth lighting","authors":"Yiqi Yu , Liming Zhang , Liuzhen Feng , Renfu Li , Zhiwen Ao , Jinmin Zhang , Ying Yang , Jinsheng Liao","doi":"10.1016/j.jlumin.2025.121697","DOIUrl":"10.1016/j.jlumin.2025.121697","url":null,"abstract":"<div><div>Cr<sup>3+</sup>-doped deep-red phosphors are ideal for plant growth lighting, yet achieving high thermal stability in tungstate hosts remains challenging. This study demonstrates that co-doping Al<sup>3+</sup> and Cr<sup>3+</sup> into the negative thermal expansion (NTE) material Sc<sub>2</sub>(WO<sub>4</sub>)<sub>3</sub> effectively strengthens the crystal field, leading to an intensified narrow-band deep-red emission from Cr<sup>3+</sup>. A series of Sc<sub>1.6</sub>Al<sub>0.4</sub>W<sub>3</sub>O<sub>12</sub>: Cr<sup>3+</sup> deep-red phosphors were successfully synthesized via solid-state reaction. The optimized Sc<sub>1.6</sub>Al<sub>0.4</sub>W<sub>3</sub>O<sub>12</sub>:0.25 %Cr<sup>3+</sup> phosphor exhibits <sup>2</sup>E → <sup>4</sup>A<sub>2</sub> emission of Cr<sup>3+</sup> at 696 nm under 406 nm excitation, matching the P<sub>FR</sub> phytochrome absorption. It retains 61.9 % of its room temperature (RT) luminescence intensity at 423 K, demonstrating superior thermal stability over analogues. The fabricated deep-red pc-LED, with its emission peak perfectly aligned with P<sub>FR</sub>, confirms its potential for plant growth lighting.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"290 ","pages":"Article 121697"},"PeriodicalIF":3.6,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.jlumin.2025.121696
Zhenxiang Ye , Xiaoting Chen , Zhen Yan , Xingyu Long , Huihui Cao , Lizhen Zhang , Lehui Liu , Yisheng Huang , Feifei Yuan , Zhoubin Lin , Hengyu Zhao
In this article, a series of DyxGd2-xSrAl2O7 (x = 0.01–0.2) polycrystalline samples were synthesized to determine the optimal Dy3+ concentration for single-crystal growth. Subsequently, a Dy:Gd2SrAl2O7 (Dy:GSAO) single crystal with Dy3+ concentration of 3.43 at.% was successfully grown using the Czochralski method. Its thermal and spectral properties were characterized. The crystal possesses low thermal expansion anisotropy (αc/αa = 1.5) and favorable thermal conductivity (4.7 W/(m·K) along the a-axis, 5.4 W/(m·K) along the c-axis), comparable to that of the YVO4 crystal (5.1 W/(m·K) along the a axis, 5.23 W/(m·K) along the c axis). Optically, the strong and broad absorption peak centered at 453 nm shows excellent spectral overlap with commercial InGaN-based blue laser diodes, enabling efficient pumping. At 453 nm, the absorption cross-sections are 2.31 × 10−21 cm2 with a FWHM of 4.74 nm for the π-polarization, and 1.31 × 10−21 cm2 with a FWHM of 5.28 nm for the σ-polarization. For the yellow emission at 582 nm, the emission cross-section are 1.81 × 10−21 cm2 (σ-polarization) and 1.50 × 10−21 cm2 (π-polarization), with FWHMs of 16.70 nm and 10.14 nm, respectively. The fluorescence lifetime of the 4F9/2 level is 198 μs. These results underscore the significant potential of the Dy:GSAO crystal as a gain medium for yellow lasers.
{"title":"Dy3+-doped Gd2SrAl2O7 crystal: A promising yellow laser material","authors":"Zhenxiang Ye , Xiaoting Chen , Zhen Yan , Xingyu Long , Huihui Cao , Lizhen Zhang , Lehui Liu , Yisheng Huang , Feifei Yuan , Zhoubin Lin , Hengyu Zhao","doi":"10.1016/j.jlumin.2025.121696","DOIUrl":"10.1016/j.jlumin.2025.121696","url":null,"abstract":"<div><div>In this article, a series of Dy<sub>x</sub>Gd<sub>2-x</sub>SrAl<sub>2</sub>O<sub>7</sub> (x = 0.01–0.2) polycrystalline samples were synthesized to determine the optimal Dy<sup>3+</sup> concentration for single-crystal growth. Subsequently, a Dy:Gd<sub>2</sub>SrAl<sub>2</sub>O<sub>7</sub> (Dy:GSAO) single crystal with Dy<sup>3+</sup> concentration of 3.43 at.% was successfully grown using the Czochralski method. Its thermal and spectral properties were characterized. The crystal possesses low thermal expansion anisotropy (α<sub><em>c</em></sub>/α<sub><em>a</em></sub> = 1.5) and favorable thermal conductivity (4.7 W/(m·K) along the a-axis, 5.4 W/(m·K) along the c-axis), comparable to that of the YVO<sub>4</sub> crystal (5.1 W/(m·K) along the a axis, 5.23 W/(m·K) along the c axis). Optically, the strong and broad absorption peak centered at 453 nm shows excellent spectral overlap with commercial InGaN-based blue laser diodes, enabling efficient pumping. At 453 nm, the absorption cross-sections are 2.31 × 10<sup>−21</sup> cm<sup>2</sup> with a FWHM of 4.74 nm for the π-polarization, and 1.31 × 10<sup>−21</sup> cm<sup>2</sup> with a FWHM of 5.28 nm for the σ-polarization. For the yellow emission at 582 nm, the emission cross-section are 1.81 × 10<sup>−21</sup> cm<sup>2</sup> (σ-polarization) and 1.50 × 10<sup>−21</sup> cm<sup>2</sup> (π-polarization), with FWHMs of 16.70 nm and 10.14 nm, respectively. The fluorescence lifetime of the <sup>4</sup>F<sub>9/2</sub> level is 198 μs. These results underscore the significant potential of the Dy:GSAO crystal as a gain medium for yellow lasers.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"290 ","pages":"Article 121696"},"PeriodicalIF":3.6,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-05DOI: 10.1016/j.jlumin.2025.121693
Lalnunpuia Khiangte, S. Rai
CdS nanoparticles doped with Ho3+ were synthesized in a silica glass matrix via the in situ sol–gel method, and their structural and optical properties were systematically investigated. Structural characterization including FTIR at 100 °C and 350 °C confirms annealing-induced modification of the silica network. TEM analysis revealed an average particle size of 29.12 nm. The CdS emission band exhibited clear spectral overlap with Ho3+ excitation, suggesting a non-radiative sensitization pathway from CdS to Ho3+ ions. Absorption spectra displayed broad CdS band-edge absorption along with sharp f–f transitions of Ho3+, and the optical bandgap was estimated as 2.9 eV using Tauc analysis. Photoluminescence studies showed both CdS host emission and characteristic Ho3+ transitions, with maximum intensity achieved at 3 mol% Ho3+ doping. CIE chromaticity analysis indicated color purity exceeding 70 % for all samples, peaking at 91.47 % for 2 mol% Ho3+. Annealing studies revealed optimal PL emission at 250 °C, attributed to hydroxyl removal and defect-state formation, while higher annealing temperatures led to ion clustering and reduced defect density. Judd–Ofelt analysis yielded Ω2 = 2.51 × 10−20 cm2, Ω4 = 1.45 × 10−20 cm2, and Ω6 = 1.31 × 10−20 cm2, with a spectroscopic quality factor of 1.10. Radiative parameters and optical gain analysis identified the 5F4 → 5I8 transition at 529 nm as the dominant green emission with high branching ratio. These findings highlight the tunable visible luminescence and favourable gain properties of Ho3+ doped CdS nanocomposites, demonstrating their potential for photonic and display applications.
{"title":"Spectroscopic properties and tunable visible emission of Ho3+ doped CdS nanoparticles in silica glass","authors":"Lalnunpuia Khiangte, S. Rai","doi":"10.1016/j.jlumin.2025.121693","DOIUrl":"10.1016/j.jlumin.2025.121693","url":null,"abstract":"<div><div>CdS nanoparticles doped with Ho<sup>3+</sup> were synthesized in a silica glass matrix via the in situ sol–gel method, and their structural and optical properties were systematically investigated. Structural characterization including FTIR at 100 °C and 350 °C confirms annealing-induced modification of the silica network. TEM analysis revealed an average particle size of 29.12 nm. The CdS emission band exhibited clear spectral overlap with Ho<sup>3+</sup> excitation, suggesting a non-radiative sensitization pathway from CdS to Ho<sup>3+</sup> ions. Absorption spectra displayed broad CdS band-edge absorption along with sharp f–f transitions of Ho<sup>3+</sup>, and the optical bandgap was estimated as 2.9 eV using Tauc analysis. Photoluminescence studies showed both CdS host emission and characteristic Ho<sup>3+</sup> transitions, with maximum intensity achieved at 3 mol% Ho<sup>3+</sup> doping. CIE chromaticity analysis indicated color purity exceeding 70 % for all samples, peaking at 91.47 % for 2 mol% Ho<sup>3+</sup>. Annealing studies revealed optimal PL emission at 250 °C, attributed to hydroxyl removal and defect-state formation, while higher annealing temperatures led to ion clustering and reduced defect density. Judd–Ofelt analysis yielded Ω<sub>2</sub> = 2.51 × 10<sup>−20</sup> cm<sup>2</sup>, Ω<sub>4</sub> = 1.45 × 10<sup>−20</sup> cm<sup>2</sup>, and Ω<sub>6</sub> = 1.31 × 10<sup>−20</sup> cm<sup>2</sup>, with a spectroscopic quality factor of 1.10. Radiative parameters and optical gain analysis identified the <sup>5</sup>F<sub>4</sub> → <sup>5</sup>I<sub>8</sub> transition at 529 nm as the dominant green emission with high branching ratio. These findings highlight the tunable visible luminescence and favourable gain properties of Ho<sup>3+</sup> doped CdS nanocomposites, demonstrating their potential for photonic and display applications.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"290 ","pages":"Article 121693"},"PeriodicalIF":3.6,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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