Pub Date : 2026-03-01Epub 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":"2026-03-01","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 : 2026-03-01Epub 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":"2026-03-01","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 : 2026-03-01Epub Date: 2025-12-18DOI: 10.1016/j.jlumin.2025.121704
M. Rahimi, A. Faeghinia
The novel Eu3+-doped oxyfluoride glasses were prepared by the melt-quenching method, with compositions following the formula (40−x) SiO2·24Al2O3·10LiF·14CaF2·12CaO·x EuF3, where x varied from 0.5 to 1.5 mol%. Structural characterization revealed densities ranging from 2.575 to 2.739 g/cm3, molar volumes from 27.81 to 26.23 cm3/mol, and hardness values between 8.21 and 9.06 GPa.
UV–Vis spectroscopy showed that increasing the concentrations of EuF3 resulted in a decrease in direct optical band gap from 3.44 eV to 3.10 eV, indicating changes in the glass matrix and electronic structure due to shifts in rare-earth ion coordination.
The use of Judd-Ofelt theory showed that Ω2 was higher than Ω4 for all glass compositions. It is noteworthy that the glasses with 1.5 mol% Eu3+ (designated G3) produced vigorous red luminescence at 610 nm, which came from the 5D0 → 7F2 transition of Eu3+. This glass's stimulated emission cross-section (σλp) was measured as 14.10 × 10−22 cm2. The gain bandwidth and optical gain parameters were found to be significant. these parameters, expressed as κ1 and κ2, were calculated to be 21.15 × 10−28 cm3 and 41.03 × 10−25 cm2s, respectively.
Color analysis yielded CIE coordinates of (0.64, 0.33), which approximate the ideal red standard, with a quantum efficiency (η) of 93 % and a red emission branching ratio (βR) of 77.67 %. These findings emphasize the suitability of these glasses for applications in red laser technology and solid-state lighting, highlighting the importance of optimizing Eu3+ doping levels to maximize optical performance for advanced optoelectronic devices.
{"title":"Effect of Eu3+ concentration on optical properties of oxyfluoride glasses for red laser applications","authors":"M. Rahimi, A. Faeghinia","doi":"10.1016/j.jlumin.2025.121704","DOIUrl":"10.1016/j.jlumin.2025.121704","url":null,"abstract":"<div><div>The novel Eu<sup>3+</sup>-doped oxyfluoride glasses were prepared by the melt-quenching method, with compositions following the formula (40−x) SiO<sub>2</sub>·24Al<sub>2</sub>O<sub>3</sub>·10LiF·14CaF<sub>2</sub>·12CaO·x EuF<sub>3</sub>, where x varied from 0.5 to 1.5 mol%. Structural characterization revealed densities ranging from 2.575 to 2.739 g/cm<sup>3</sup>, molar volumes from 27.81 to 26.23 cm<sup>3</sup>/mol, and hardness values between 8.21 and 9.06 GPa.</div><div>UV–Vis spectroscopy showed that increasing the concentrations of EuF<sub>3</sub> resulted in a decrease in direct optical band gap from 3.44 eV to 3.10 eV, indicating changes in the glass matrix and electronic structure due to shifts in rare-earth ion coordination.</div><div>The use of Judd-Ofelt theory showed that Ω<sub>2</sub> was higher than Ω<sub>4</sub> for all glass compositions. It is noteworthy that the glasses with 1.5 mol% Eu<sup>3+</sup> (designated G<sub>3</sub>) produced vigorous red luminescence at 610 nm, which came from the <sup>5</sup>D<sub>0</sub> → <sup>7</sup>F<sub>2</sub> transition of Eu<sup>3+</sup>. This glass's stimulated emission cross-section (σ<sub>λp</sub>) was measured as 14.10 × 10<sup>−22</sup> cm<sup>2</sup>. The gain bandwidth and optical gain parameters were found to be significant. these parameters, expressed as κ<sub>1</sub> and κ<sub>2</sub>, were calculated to be 21.15 × 10<sup>−28</sup> cm<sup>3</sup> and 41.03 × 10<sup>−25</sup> cm<sup>2</sup>s, respectively.</div><div>Color analysis yielded CIE coordinates of (0.64, 0.33), which approximate the ideal red standard, with a quantum efficiency (η) of 93 % and a red emission branching ratio (β<sub>R</sub>) of 77.67 %. These findings emphasize the suitability of these glasses for applications in red laser technology and solid-state lighting, highlighting the importance of optimizing Eu<sup>3+</sup> doping levels to maximize optical performance for advanced optoelectronic devices.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121704"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838656","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 : 2026-03-01Epub Date: 2025-12-28DOI: 10.1016/j.jlumin.2025.121729
Chunyue Yu, Hang Yin, Jie Guo, Ying Shi
Metal-free organic thermally activated delayed fluorescence (TADF) materials hold significant promise for optoelectronic applications. Remarkably, Fu et al. achieved simultaneous regulation of the photoluminescence quantum yields (PLQY) of the chromophores by fluorine substitution, with HPI2C-F and HPI2C-3F showing significantly higher PLQY than HPI2C, while HPI2C-2F shows a slight decrease in comparison to HPI2C [Adv. Opt. Mater. 12, 2303025 (2024)]. However, several unresolved questions regarding the mechanism of simultaneous PLQY regulation require further theoretical investigations. Specifically, what are the key factors that contribute to the significant differences in PLQY across the HPI2C derivatives? Which excited state is crucial in improving the efficiency of triplet exciton utilization? What is the interaction mechanism between excited-state intramolecular proton transfer (ESIPT) and TADF? Herein, the TADF mechanisms of HPI2C-F, HPI2C-2F, and HPI2C-3F molecules are systematically investigated using the optimally tuned range-separated density functional theory. We verify the key role of the T2 state in the TADF process that involves the Keto∗ state of the fluoro-substituted HPI2C derivatives. Moreover, we reveal that the energy inversion of singlet and triplet excited states (negative ΔEST) facilitates reverse intersystem crossing (RISC), resulting in significantly enhanced delayed fluorescence and ultimately improved PLQY for HPI2C-F and HPI2C-3F. Meanwhile, the STEOM-DLPNO-CCSD method and double-hybrid density functional theory were employed to confirm the reliability of the optimally tuned range-separated functionals in calculating the TADF mechanisms of the fluoro-substituted HPI2C derivatives. This investigation not only provides deep insights into the efficient TADF mechanisms, but also demonstrates the accuracy and effectiveness of optimally tuned range-separated functionals in predicting the luminescent properties of metal-free organic TADF materials.
{"title":"Optimally tuned range-separated functionals unravel efficient TADF mechanisms in HPI2C derivatives","authors":"Chunyue Yu, Hang Yin, Jie Guo, Ying Shi","doi":"10.1016/j.jlumin.2025.121729","DOIUrl":"10.1016/j.jlumin.2025.121729","url":null,"abstract":"<div><div>Metal-free organic thermally activated delayed fluorescence (TADF) materials hold significant promise for optoelectronic applications. Remarkably, Fu et al. achieved simultaneous regulation of the photoluminescence quantum yields (PLQY) of the chromophores by fluorine substitution, with HPI2C-F and HPI2C-3F showing significantly higher PLQY than HPI2C, while HPI2C-2F shows a slight decrease in comparison to HPI2C [Adv. Opt. Mater. 12, 2303025 (2024)]. However, several unresolved questions regarding the mechanism of simultaneous PLQY regulation require further theoretical investigations. Specifically, what are the key factors that contribute to the significant differences in PLQY across the HPI2C derivatives? Which excited state is crucial in improving the efficiency of triplet exciton utilization? What is the interaction mechanism between excited-state intramolecular proton transfer (ESIPT) and TADF? Herein, the TADF mechanisms of HPI2C-F, HPI2C-2F, and HPI2C-3F molecules are systematically investigated using the optimally tuned range-separated density functional theory. We verify the key role of the T<sub>2</sub> state in the TADF process that involves the Keto∗ state of the fluoro-substituted HPI2C derivatives. Moreover, we reveal that the energy inversion of singlet and triplet excited states (negative ΔE<sub>ST</sub>) facilitates reverse intersystem crossing (RISC), resulting in significantly enhanced delayed fluorescence and ultimately improved PLQY for HPI2C-F and HPI2C-3F. Meanwhile, the STEOM-DLPNO-CCSD method and double-hybrid density functional theory were employed to confirm the reliability of the optimally tuned range-separated functionals in calculating the TADF mechanisms of the fluoro-substituted HPI2C derivatives. This investigation not only provides deep insights into the efficient TADF mechanisms, but also demonstrates the accuracy and effectiveness of optimally tuned range-separated functionals in predicting the luminescent properties of metal-free organic TADF materials.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121729"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881423","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}
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":"2026-03-01","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}
Pub Date : 2026-03-01Epub Date: 2025-12-27DOI: 10.1016/j.jlumin.2025.121728
Jiaan Gao, Yifu Zhang, Xiaonan Wang, Siqi Wang, Hui Li
This study employs density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations to investigate the excited-state intramolecular proton transfer (ESIPT) behaviors of HBOB and its hydrazine derivative HBON in n-heptane, with a particular emphasis on their modulation by external electric fields (EEFs). Both molecules possess multiple hydrogen-bond donors and acceptors, enabling two distinct ESIPT pathways, categorized as imine-type (Channel 1) and hydrazone-type (Channel 2) derivatives. Boltzmann analysis shows that both the imine-type and hydrazone-type tautomers are accessible, enabling two parallel proton-transfer pathways upon photoexcitation. In the absence of EEFs, both molecular systems are capable of undergoing Dual-Channel ESIPT. Consequently, Channel 2 is kinetically favored in HBOB, while HBON shows a modest thermodynamic stabilization of the Channel 1 Keto∗ species. Moreover, Channel 2 exhibits a barrierless ESIPT for HBOB-7 and HBON-3, with HBOB-7 initiating proton transfer earlier. This intrinsic energetic asymmetry explains why EEFs selectively enhance different pathways in the two systems. Theoretical results confirm that, upon application of EEFs, a negative EEF facilitates proton transfer in the reactant molecules HBOB-1 and HBOB-7, while a positive EEF promotes proton transfer along Channel 1 and Channel 2 in the product molecules HBON-1 and HBON-3. These findings provide valuable insights into the EEF-regulated ESIPT mechanisms and underscore the potential of external electric fields as precise and versatile tools for tailoring excited-state behaviors in hydrogen-bonded systems.
{"title":"Tunable dual ESIPT pathways directed by external electric fields: A TDDFT exploration of HBOB/HBON systems","authors":"Jiaan Gao, Yifu Zhang, Xiaonan Wang, Siqi Wang, Hui Li","doi":"10.1016/j.jlumin.2025.121728","DOIUrl":"10.1016/j.jlumin.2025.121728","url":null,"abstract":"<div><div>This study employs density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations to investigate the excited-state intramolecular proton transfer (ESIPT) behaviors of HBOB and its hydrazine derivative HBON in n-heptane, with a particular emphasis on their modulation by external electric fields (EEFs). Both molecules possess multiple hydrogen-bond donors and acceptors, enabling two distinct ESIPT pathways, categorized as imine-type (Channel 1) and hydrazone-type (Channel 2) derivatives. Boltzmann analysis shows that both the imine-type and hydrazone-type tautomers are accessible, enabling two parallel proton-transfer pathways upon photoexcitation. In the absence of EEFs, both molecular systems are capable of undergoing Dual-Channel ESIPT. Consequently, Channel 2 is kinetically favored in HBOB, while HBON shows a modest thermodynamic stabilization of the Channel 1 Keto∗ species. Moreover, Channel 2 exhibits a barrierless ESIPT for HBOB-7 and HBON-3, with HBOB-7 initiating proton transfer earlier. This intrinsic energetic asymmetry explains why EEFs selectively enhance different pathways in the two systems. Theoretical results confirm that, upon application of EEFs, a negative EEF facilitates proton transfer in the reactant molecules HBOB-1 and HBOB-7, while a positive EEF promotes proton transfer along Channel 1 and Channel 2 in the product molecules HBON-1 and HBON-3. These findings provide valuable insights into the EEF-regulated ESIPT mechanisms and underscore the potential of external electric fields as precise and versatile tools for tailoring excited-state behaviors in hydrogen-bonded systems.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121728"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881424","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":"2026-03-01","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 : 2026-03-01Epub Date: 2025-12-22DOI: 10.1016/j.jlumin.2025.121721
Biao Han , Yanan Xu , Chaomin Zhang , Guishun Li , Xingyu Liu , Yongji Wei
The development of mid-infrared (MIR) laser materials with broadband emission and high thermal stability remains challenging, as existing systems often rely on complex co-doping strategies such as Er3+/Yb3+ or suffer from limited emission bandwidth. In this work, we propose a novel Er3+-singly doped tellurite glass (70TeO2-10ZnO-5Nb2O5-5Bi2O3-10Ga2O3-xEr2O3) fabricated via high-temperature melting and quenching. The differential scanning calorimetry curve ΔT (123 °C)>120 °C suggests that the glass sample possesses an outstanding anti-crystallization properties, attributed to the synergistic effects of high-polarization oxides (Nb2O5, Bi2O3) and intermediate Ga2O3. Under 980 nm LD excitation, the glass exhibits dual-band fluorescence: a 1.5 μm near-infrared (NIR) emission (1400–1700 nm) from the Er3+: 4I13/2 → 4I15/2 transition, and a MIR emission at 2.7 μm (2550–2950 nm) with a full width at half maximum (FWHM) of 183 nm, surpassing previous Er3+-singly doped glasses. The broad spectral originates from enhanced structural disorder induced by Nb5+/Bi3+-modified TeO2 networks, which create diverse Er3+ coordination environments. Energy transfer analysis confirms suppressed ion clustering due to the tailored glass matrix, enabling efficient radiative transitions. Our work demonstrates that single-doped Er3+ tellurite glasses offer a simple and effective route for MIR broadband gain media, particularly for fiber lasers and sensing applications.
{"title":"Broadband mid-infrared fluorescence emission at 2.7 μm in Er3+-doped tellurite glasses","authors":"Biao Han , Yanan Xu , Chaomin Zhang , Guishun Li , Xingyu Liu , Yongji Wei","doi":"10.1016/j.jlumin.2025.121721","DOIUrl":"10.1016/j.jlumin.2025.121721","url":null,"abstract":"<div><div>The development of mid-infrared (MIR) laser materials with broadband emission and high thermal stability remains challenging, as existing systems often rely on complex co-doping strategies such as Er<sup>3+</sup>/Yb<sup>3+</sup> or suffer from limited emission bandwidth. In this work, we propose a novel Er<sup>3+</sup>-singly doped tellurite glass (70TeO<sub>2</sub>-10ZnO-5Nb<sub>2</sub>O<sub>5</sub>-5Bi<sub>2</sub>O<sub>3</sub>-10Ga<sub>2</sub>O<sub>3</sub>-xEr<sub>2</sub>O<sub>3</sub>) fabricated via high-temperature melting and quenching. The differential scanning calorimetry curve ΔT (123 °C)>120 °C suggests that the glass sample possesses an outstanding anti-crystallization properties, attributed to the synergistic effects of high-polarization oxides (Nb<sub>2</sub>O<sub>5</sub>, Bi<sub>2</sub>O<sub>3</sub>) and intermediate Ga<sub>2</sub>O<sub>3</sub>. Under 980 nm LD excitation, the glass exhibits dual-band fluorescence: a 1.5 μm near-infrared (NIR) emission (1400–1700 nm) from the Er<sup>3+</sup>: <sup>4</sup>I<sub>13/2</sub> → <sup>4</sup>I<sub>15/2</sub> transition, and a MIR emission at 2.7 μm (2550–2950 nm) with a full width at half maximum (FWHM) of 183 nm, surpassing previous Er<sup>3+</sup>-singly doped glasses. The broad spectral originates from enhanced structural disorder induced by Nb<sup>5+</sup>/Bi<sup>3+</sup>-modified TeO<sub>2</sub> networks, which create diverse Er<sup>3+</sup> coordination environments. Energy transfer analysis confirms suppressed ion clustering due to the tailored glass matrix, enabling efficient radiative transitions. Our work demonstrates that single-doped Er<sup>3+</sup> tellurite glasses offer a simple and effective route for MIR broadband gain media, particularly for fiber lasers and sensing applications.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121721"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838653","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}
In this paper, Cs2NaRECl6 (RE = Yb0.9Er0.1, Tb, Eu) microncrystals (MCs) were synthesized via a facile solvent-thermal method with the ethanol-water mixture (95.6∶4.4, m/m) as solvent. The prepared MCs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). Photoluminescence (PL) properties of prepared MCs were measured and possible luminescent processes were given.
{"title":"Solvent-thermal synthesis and photoluminescence properties of rare-earth based double perovskite Cs2NaRECl6 (RE = Yb0.9Er0.1, Tb, Eu) microcrystals","authors":"Ruifei Qin, Lina Liu, Chunjuan Tang, Guanglei Guo, Kexin Wang, Jia Liu, Feng Shan","doi":"10.1016/j.jlumin.2025.121722","DOIUrl":"10.1016/j.jlumin.2025.121722","url":null,"abstract":"<div><div>In this paper, Cs<sub>2</sub>NaRECl<sub>6</sub> (RE = Yb<sub>0.9</sub>Er<sub>0.1</sub>, Tb, Eu) microncrystals (MCs) were synthesized via a facile solvent-thermal method with the ethanol-water mixture (95.6∶4.4, m/m) as solvent. The prepared MCs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). Photoluminescence (PL) properties of prepared MCs were measured and possible luminescent processes were given.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121722"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838654","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}
Broadband yellow-green-emitting materials help to improve the color rendition performance of phosphor-converted white light-emitting diodes (pc-WLEDs). Herein, we report a Bi3+-activated double perovskite (La2MgHfO6) broadband yellow-green-emitting phosphor synthesized via high-temperature solid-state reaction. Structural characterization confirms phase-pure crystallization in the P21/n space group, while spectral analysis reveals a broad yellow-green emission (λem = 544 nm, FWHM = 137 nm) under 370 nm excitation, attributed to the parity-allowed 3P1→1S0 transition of Bi3+ in [LaO8] dodecahedron and [Mg/HfO6] octahedra. The material effectively suppresses concentration quenching owing to the relatively large interionic distances within its crystal structure. Meanwhile, its emission peak exhibits a red-shifting (Δλ = 30 nm) with varying excitation wavelengths, which stems from the distinct responses of different luminescent centers to excitation energy. Additionally, it demonstrates good thermal stability, with minimal temperature-induced changes in peak position and full width at half maximum (FWHM). When combined with commercial red (CaAlSiN3:Eu2+) and blue (BAM:Eu2+) phosphors, the fabricated WLED exhibits bright white light with superior color rendering (Ra = 86.9) and comfortable correlated color temperature (CCT = 4994 K). The yellow-green emission significantly enhances spectral continuity, demonstrating great potential as a rare-earth-free component for high-quality full-spectrum lighting systems.
{"title":"Broadband yellow-green emitting Bi3+-doped La2MgHfO6 double perovskite phosphor for WLED","authors":"Xinyi Zhang, Wenqi Xia, Zehua Xue, Wanyu Zhao, Xiyuan Zhang, Zuobin Tang","doi":"10.1016/j.jlumin.2025.121719","DOIUrl":"10.1016/j.jlumin.2025.121719","url":null,"abstract":"<div><div>Broadband yellow-green-emitting materials help to improve the color rendition performance of phosphor-converted white light-emitting diodes (pc-WLEDs). Herein, we report a Bi<sup>3+</sup>-activated double perovskite (La<sub>2</sub>MgHfO<sub>6</sub>) broadband yellow-green-emitting phosphor synthesized via high-temperature solid-state reaction. Structural characterization confirms phase-pure crystallization in the P21/n space group, while spectral analysis reveals a broad yellow-green emission (λ<sub>em</sub> = 544 nm, FWHM = 137 nm) under 370 nm excitation, attributed to the parity-allowed <sup>3</sup>P<sub>1</sub>→<sup>1</sup>S<sub>0</sub> transition of Bi<sup>3+</sup> in [LaO<sub>8</sub>] dodecahedron and [Mg/HfO<sub>6</sub>] octahedra. The material effectively suppresses concentration quenching owing to the relatively large interionic distances within its crystal structure. Meanwhile, its emission peak exhibits a red-shifting (Δλ = 30 nm) with varying excitation wavelengths, which stems from the distinct responses of different luminescent centers to excitation energy. Additionally, it demonstrates good thermal stability, with minimal temperature-induced changes in peak position and full width at half maximum (FWHM). When combined with commercial red (CaAlSiN<sub>3</sub>:Eu<sup>2+</sup>) and blue (BAM:Eu<sup>2+</sup>) phosphors, the fabricated WLED exhibits bright white light with superior color rendering (Ra = 86.9) and comfortable correlated color temperature (CCT = 4994 K). The yellow-green emission significantly enhances spectral continuity, demonstrating great potential as a rare-earth-free component for high-quality full-spectrum lighting systems.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"291 ","pages":"Article 121719"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838659","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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