Pub Date : 2024-10-01DOI: 10.1016/j.jlumin.2024.120922
P.J. Gracie, D. Geetha
The multi-component silicate glass films triply-doped with Er3+/Yb3+/Nd3+ were fabricated by spin coating technique. X-ray diffraction revealed a cristobalite phase in the glasses doped above 0.6 mol% of Nd3+. The transparency of the films increases with the addition of the co-dopant, due to the increase in optical band gap by the Burstein-Moss shift. The high value of the correlated color temperature of the blue emission indicates enhanced visual perception, suggestive of cool blue film lasers. The red emission from upconversion exhibits potentiality for flat display panels. The gain cross-section of the glass with 0.6 mol% of Nd3+ was 13.54 cm2 which makes it ideal for NIR film lasers in the S-band region. The Inokuti-Hirayama model predicts luminescence quenching due to dipole-dipole interactions in the glasses co-doped beyond 0.6 mol% of Nd3+. The transition observed in the films, suggests their suitability for O + E + S band NIR film lasers in telecommunication sectors.
通过旋涂技术制备了三掺杂 Er3+/Yb3+/Nd3+ 的多组分硅酸盐玻璃薄膜。X 射线衍射显示，在掺杂了 0.6 mol% 以上 Nd3+ 的玻璃中存在嵴钙钛矿相。薄膜的透明度随着共掺杂剂的加入而增加，这是由于伯斯坦-莫斯偏移导致光带隙增大。蓝色发射的相关色温值较高，表明视觉感知能力增强，这也是冷蓝色薄膜激光器的特征。上转换产生的红色发射显示出平面显示面板的潜力。含有 0.6 mol% Nd3+ 的玻璃的增益截面为 13.54 ×10-20 cm2，这使其成为 S 波段近红外薄膜激光器的理想选择。根据 Inokuti-Hirayama 模型的预测，掺杂超过 0.6 mol% Nd3+ 的玻璃中的偶极-偶极相互作用会导致发光淬灭。在薄膜中观察到的 4F9/2→4I13/2 转变表明，它们适用于电信领域的 O + E + S 波段近红外薄膜激光器。
{"title":"Explication of the luminescent and optically active RE3+ triply-doped silica phosphate glass films for photonic applications","authors":"P.J. Gracie, D. Geetha","doi":"10.1016/j.jlumin.2024.120922","DOIUrl":"10.1016/j.jlumin.2024.120922","url":null,"abstract":"<div><div>The multi-component silicate glass films triply-doped with Er<sup>3+</sup>/Yb<sup>3+</sup>/Nd<sup>3+</sup> were fabricated by spin coating technique. X-ray diffraction revealed a cristobalite phase in the glasses doped above 0.6 mol% of Nd<sup>3+</sup>. The transparency of the films increases with the addition of the co-dopant, due to the increase in optical band gap by the Burstein-Moss shift. The high value of the correlated color temperature of the blue emission indicates enhanced visual perception, suggestive of cool blue film lasers. The red emission from upconversion exhibits potentiality for flat display panels. The gain cross-section of the glass with 0.6 mol% of Nd<sup>3+</sup> was 13.54 <span><math><mrow><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>20</mn></mrow></msup></mrow></math></span> cm<sup>2</sup> which makes it ideal for NIR film lasers in the S-band region. The Inokuti-Hirayama model predicts luminescence quenching due to dipole-dipole interactions in the glasses co-doped beyond 0.6 mol% of Nd<sup>3+</sup>. The <span><math><mrow><mn>4</mn><msub><mi>F</mi><mrow><mn>9</mn><mo>/</mo><mn>2</mn></mrow></msub><mo>→</mo><mn>4</mn><msub><mi>I</mi><mrow><mn>13</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></math></span> transition observed in the films, suggests their suitability for O + E + S band NIR film lasers in telecommunication sectors.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120922"},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423549","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 spectral and kinetic properties of intrinsic luminescence from (Y2Sc1)0.(3)(Sc)[Si]O5 crystal are studied. The emission is excited by electrons and γ-quanta. The composition (Y2Sc1)0.(3)(Sc)[Si]O5 is the congruent one for Sc2SiO5-Y2SiO5 solid solutions. It is found, that the crystal emits fairly bright intrinsic cathodololuminescence (CL) and radioluminescence (RL) at room temperature. In particular, the light yield of scintillation excited by γ-quanta with the energies of 661.7 keV is of 12000 photons/MeV. An increase in the beam flux by ∼20 times leads to the shift in the maximal CL energy spectral density from 315 to 340 nm and to the decrease in the CL decay time at 415 nm from 1377 ± 3 ns to 1165 ± 1 ns. Simultaneously, the decay time of RL excited by a photoelectron with the energy of 644.7 keV is of 1310 ± 10 ns while a Compton electron with the energy of 477 keV excites RL with the decay time of 1050 ± 10 ns. Also, we observed differences in the CL yield dependencies on the volume-averaged density of electronic excitations (EEs) at different wavelengths. An explanation of the results is given considering the nonlinear scintillation phenomena induced by an interaction between EEs. It is based on a conception that an increase in EE volume density leads to an increase in EEs nonradiative quenching due to these interactions.
{"title":"Nonlinear scintillation effects in the intrinsic luminescence from Sc1.318Y0.655Si1.013O4.987 crystal excited by electrons and γ-quanta","authors":"M.V. Belov , V.A. Kozlov , N.V. Pestovskii , S.Yu. Savinov , V.S. Tskhay , V.I. Vlasov , A.I. Zagumennyi , Yu.D. Zavartsev , M.V. Zavertyaev","doi":"10.1016/j.jlumin.2024.120919","DOIUrl":"10.1016/j.jlumin.2024.120919","url":null,"abstract":"<div><div>The spectral and kinetic properties of intrinsic luminescence from (Y<sub>2</sub>Sc<sub>1</sub>)<sub>0.(3)</sub>(Sc)[Si]O<sub>5</sub> crystal are studied. The emission is excited by electrons and <em>γ</em>-quanta. The composition (Y<sub>2</sub>Sc<sub>1</sub>)<sub>0.(3)</sub>(Sc)[Si]O<sub>5</sub> is the congruent one for Sc<sub>2</sub>SiO<sub>5</sub>-Y<sub>2</sub>SiO<sub>5</sub> solid solutions. It is found, that the crystal emits fairly bright intrinsic cathodololuminescence (CL) and radioluminescence (RL) at room temperature. In particular, the light yield of scintillation excited by <em>γ</em>-quanta with the energies of 661.7 keV is of 12000 photons/MeV. An increase in the beam flux by ∼20 times leads to the shift in the maximal CL energy spectral density from 315 to 340 nm and to the decrease in the CL decay time at 415 nm from 1377 ± 3 ns to 1165 ± 1 ns. Simultaneously, the decay time of RL excited by a photoelectron with the energy of 644.7 keV is of 1310 ± 10 ns while a Compton electron with the energy of 477 keV excites RL with the decay time of 1050 ± 10 ns. Also, we observed differences in the CL yield dependencies on the volume-averaged density of electronic excitations (EEs) at different wavelengths. An explanation of the results is given considering the nonlinear scintillation phenomena induced by an interaction between EEs. It is based on a conception that an increase in EE volume density leads to an increase in EEs nonradiative quenching due to these interactions.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120919"},"PeriodicalIF":3.3,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423547","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 : 2024-09-30DOI: 10.1016/j.jlumin.2024.120924
Heng Guo
Low-dimensional metal halides, which possess efficient luminescent properties, have garnered significant interest in the fields of optoelectronics and radiation detection. This study introduces novel lead-free silver-based metal halide material, CsAgCl2 microcrystals (MCs). These MCs have a one-dimensional atomic chain structure and a unique [AgCl5]4- tetragonal shared triangular configuration. CsAgCl2 MCs exhibit excellent performance as X-ray scintillators due to their bright broadband yellow emission and fast decay time in the microsecond range. The large Stokes shift of 350 nm is produced by self-trapped exciton emission. In X-ray scintillation applications, CsAgCl2 MCs demonstrate a high light yield of 13280 photons/MeV and a wide range of linear scintillation response. It is noteworthy that the CsAgCl2 MCs maintain good stability under both atmospheric conditions and continuous X-ray irradiation. The sample was used in an X-ray imaging screen, which clearly presented the X-ray projection image of a wooden stick. As a result, this research not only contributes to the collection of lead-free metal halide scintillators but also indicates that CsAgCl2 MCs have a wide range of future applications and potential in areas such as medical imaging, scientific research, and diagnostic and detection technologies.
低维金属卤化物具有高效发光特性，在光电子学和辐射探测领域备受关注。本研究介绍了新型无铅银基金属卤化物材料 CsAgCl2 微晶（MCs）。这些微晶具有一维原子链结构和独特的[AgCl5]4- 四方共三角形构型。CsAgCl2 MCs 具有明亮的宽带黄色发射和微秒级的快速衰减时间，因此作为 X 射线闪烁体表现出卓越的性能。350 纳米的大斯托克斯偏移是由自俘获激子发射产生的。在 X 射线闪烁应用中，CsAgCl2 MCs 表现出 13280 光子/兆电子伏的高光产率和宽范围的线性闪烁响应。值得注意的是，CsAgCl2 MCs 在大气条件和连续 X 射线辐照下都能保持良好的稳定性。该样品被用于 X 射线成像屏幕，能清晰地呈现木棒的 X 射线投影图像。因此，这项研究不仅有助于收集无铅金属卤化物闪烁体，还表明 CsAgCl2 MCs 未来在医学成像、科学研究、诊断和检测技术等领域具有广泛的应用前景和潜力。
{"title":"Synthesis of low-dimensional metal halide CsAgCl2 for X-ray scintillation applications","authors":"Heng Guo","doi":"10.1016/j.jlumin.2024.120924","DOIUrl":"10.1016/j.jlumin.2024.120924","url":null,"abstract":"<div><div>Low-dimensional metal halides, which possess efficient luminescent properties, have garnered significant interest in the fields of optoelectronics and radiation detection. This study introduces novel lead-free silver-based metal halide material, CsAgCl<sub>2</sub> microcrystals (MCs). These MCs have a one-dimensional atomic chain structure and a unique [AgCl<sub>5</sub>]<sup>4-</sup> tetragonal shared triangular configuration. CsAgCl<sub>2</sub> MCs exhibit excellent performance as X-ray scintillators due to their bright broadband yellow emission and fast decay time in the microsecond range. The large Stokes shift of 350 nm is produced by self-trapped exciton emission. In X-ray scintillation applications, CsAgCl<sub>2</sub> MCs demonstrate a high light yield of 13280 photons/MeV and a wide range of linear scintillation response. It is noteworthy that the CsAgCl<sub>2</sub> MCs maintain good stability under both atmospheric conditions and continuous X-ray irradiation. The sample was used in an X-ray imaging screen, which clearly presented the X-ray projection image of a wooden stick. As a result, this research not only contributes to the collection of lead-free metal halide scintillators but also indicates that CsAgCl<sub>2</sub> MCs have a wide range of future applications and potential in areas such as medical imaging, scientific research, and diagnostic and detection technologies.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120924"},"PeriodicalIF":3.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423545","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 : 2024-09-30DOI: 10.1016/j.jlumin.2024.120921
Jinghua Zhang , Yue Tang , Qichuan Duan , Yaling Wang , Xiaoqiang Tong , Dongliang Tao , Rongbao Liao , Feng Jin , Kun Yin , Deqian Huang , Shangrong Zhang
Two-photon excited fluorescence (TPEF) is widely sought after in bioimaging applications due to its exceptional deep tissue penetration and excellent high spatiotemporal resolution. In this paper, benzothiazole and benzimidazole are linked to N, N-diphenylaniline, respectively, through pyridine vinyl. Two new D-π-A (electron donor-π conjugated bridges-electron acceptor) probes (P1, P2) were designed and synthesized. The molecular structures were completely characterized through FT-IR, 1H NMR, 13C NMR, ESI-MS, and X-ray single crystal diffraction. The probes have good one-photon excited fluorescence and two-photon excited fluorescence. Experimental test results indicate that they can be fluorescence probes for biological imaging of HePG2 and juvenile zebrafish. In addition, the fluorescent probes also have the ability to target and locate cancer cell mitochondria.
双光子激发荧光（TPEF）因其卓越的深层组织穿透性和出色的高时空分辨率而在生物成像应用中广受欢迎。在本文中，苯并噻唑和苯并咪唑通过吡啶基分别与 N，N-二苯基苯胺相连。设计并合成了两种新的 D-π-A（电子供体-π共轭桥-电子受体）探针（P1、P2）。通过傅立叶变换红外光谱（FT-IR）、1H NMR、13C NMR、ESI-MS 和 X 射线单晶衍射对分子结构进行了完整的表征。探针具有良好的单光子激发荧光和双光子激发荧光。实验测试结果表明，这些探针可用于 HePG2 和幼年斑马鱼的生物成像。此外，该荧光探针还具有靶向定位癌细胞线粒体的能力。
{"title":"Small molecule probes with strong one and two-photon excited fluorescence for bioimaging","authors":"Jinghua Zhang , Yue Tang , Qichuan Duan , Yaling Wang , Xiaoqiang Tong , Dongliang Tao , Rongbao Liao , Feng Jin , Kun Yin , Deqian Huang , Shangrong Zhang","doi":"10.1016/j.jlumin.2024.120921","DOIUrl":"10.1016/j.jlumin.2024.120921","url":null,"abstract":"<div><div>Two-photon excited fluorescence (TPEF) is widely sought after in bioimaging applications due to its exceptional deep tissue penetration and excellent high spatiotemporal resolution. In this paper, benzothiazole and benzimidazole are linked to N, N-diphenylaniline, respectively, through pyridine vinyl. Two new D-π-A (electron donor-π conjugated bridges-electron acceptor) probes (P1, P2) were designed and synthesized. The molecular structures were completely characterized through FT-IR, <sup>1</sup>H NMR, <sup>13</sup>C NMR, ESI-MS, and X-ray single crystal diffraction. The probes have good one-photon excited fluorescence and two-photon excited fluorescence. Experimental test results indicate that they can be fluorescence probes for biological imaging of HePG2 and juvenile zebrafish. In addition, the fluorescent probes also have the ability to target and locate cancer cell mitochondria.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120921"},"PeriodicalIF":3.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423420","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 : 2024-09-28DOI: 10.1016/j.jlumin.2024.120899
Reshma J. Pandhare , Sajeev Chacko , Rajesh M. Kamble
A series of eight novel donor‒acceptor (D─A) based 2,3-di(thiophen-2-yl)quinoxaline derivatives 2–9 were prepared by modulating donor species on quinoxaline core with Palladium catalyzed Suzuki–Miyaura ‘C–C bond’ coupling reaction. The synthesized molecules were fully characterized and studied for impact of D–A interaction on opto-electrochemical properties. Absorption spectra of 2–9 display intramolecular charge transfer (ICT) transitions in the range of 388–414 nm. Dyes shows positive solvatochromism and emit in blue‒yellow region with emission maxima 444−550 nm on excitation at their respective ICT maxima in toluene, chloroform, DCM, DMSO and neat solid film. Further, solid state emission was studied for aggregation‒induced emission (AIE) effect in THF–water system due to the nanoparticles formation, as confirmed by FEG‒SEM technique. The HOMO and LUMO energy level for compounds 2–9 were measured by cyclic voltammetry and found in the range of −5.15 to −5.94 eV and −2.81 to −3.39 eV. Theoretical studies of molecules were also carried out by using DFT and TD‒DFT calculations. The comparable HOMO and LUMO energy levels with reported ambipolar materials and efficient solid-state emission make synthesized compounds potential candidate for solid state emissive, ambipolar charge transporting materials in organic electronics.
{"title":"Suzuki-Miyaura coupling reaction: Blue-yellow emitting AIE active dyes for organic electronics","authors":"Reshma J. Pandhare , Sajeev Chacko , Rajesh M. Kamble","doi":"10.1016/j.jlumin.2024.120899","DOIUrl":"10.1016/j.jlumin.2024.120899","url":null,"abstract":"<div><div>A series of eight novel donor‒acceptor (D─A) based 2,3-di(thiophen-2-yl)quinoxaline derivatives <strong>2</strong>–<strong>9</strong> were prepared by modulating donor species on quinoxaline core with Palladium catalyzed Suzuki–Miyaura ‘C–C bond’ coupling reaction. The synthesized molecules were fully characterized and studied for impact of D–A interaction on opto-electrochemical properties. Absorption spectra of <strong>2</strong>–<strong>9</strong> display intramolecular charge transfer (ICT) transitions in the range of 388–414 nm. Dyes shows positive solvatochromism and emit in blue‒yellow region with emission maxima 444−550 nm on excitation at their respective ICT maxima in toluene, chloroform, DCM, DMSO and neat solid film. Further, solid state emission was studied for aggregation‒induced emission (AIE) effect in THF–water system due to the nanoparticles formation, as confirmed by FEG‒SEM technique. The HOMO and LUMO energy level for compounds <strong>2</strong>–<strong>9</strong> were measured by cyclic voltammetry and found in the range of −5.15 to −5.94 eV and −2.81 to −3.39 eV. Theoretical studies of molecules were also carried out by using DFT and TD‒DFT calculations. The comparable HOMO and LUMO energy levels with reported ambipolar materials and efficient solid-state emission make synthesized compounds potential candidate for solid state emissive, ambipolar charge transporting materials in organic electronics.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120899"},"PeriodicalIF":3.3,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423544","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 : 2024-09-26DOI: 10.1016/j.jlumin.2024.120915
Wei Yuan , Rongbin Dai , Zheng Zhang , Xiuji Lin , Huiying Xu , Zhiping Cai
In order to study the spectral properties of Ho3+:YLiF4 (Ho3+:YLF), we measured the absorption spectra f Ho3+:YLF crystal. The experimental and calculated electric dipole line strength are calculated based on Judd-Ofelt theory, so do other spectral parameters. In order to characterize the emission characteristics of energy level, we measured the emission spectra of Ho3+:YLF crystal under the pumping of lasers at 450 nm and 640 nm, and the partial emission cross-sections spectra was calculated according to the Fuchtbauer-Ladenburg theory. Moreover, the fluorescence lifetimes of 537 nm, 656 nm, 750 nm, 1195 nm and 1964 nm are measured. As far as we know, the fluorescence lifetime of 1964 nm (∼2 μm) and the emission cross-sections of ∼750 nm and ∼961 nm are confirmed for the first time. This work lays the foundation for the generation of lasing at novel wavelength on Ho3+:YLF crystal.
{"title":"Spectral analysis and emission properties of Ho3+: YLF in the visible-near infrared band","authors":"Wei Yuan , Rongbin Dai , Zheng Zhang , Xiuji Lin , Huiying Xu , Zhiping Cai","doi":"10.1016/j.jlumin.2024.120915","DOIUrl":"10.1016/j.jlumin.2024.120915","url":null,"abstract":"<div><div>In order to study the spectral properties of Ho<sup>3+</sup>:YLiF<sub>4</sub> (Ho<sup>3+</sup>:YLF), we measured the absorption spectra f Ho<sup>3+</sup>:YLF crystal. The experimental and calculated electric dipole line strength are calculated based on Judd-Ofelt theory, so do other spectral parameters. In order to characterize the emission characteristics of energy level, we measured the emission spectra of Ho<sup>3+</sup>:YLF crystal under the pumping of lasers at 450 nm and 640 nm, and the partial emission cross-sections spectra was calculated according to the Fuchtbauer-Ladenburg theory. Moreover, the fluorescence lifetimes of 537 nm, 656 nm, 750 nm, 1195 nm and 1964 nm are measured. As far as we know, the fluorescence lifetime of 1964 nm (∼2 μm) and the emission cross-sections of ∼750 nm and ∼961 nm are confirmed for the first time. This work lays the foundation for the generation of lasing at novel wavelength on Ho<sup>3+</sup>:YLF crystal.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120915"},"PeriodicalIF":3.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327869","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}
A series of novel red-emitting Sr2EuAlO5 phosphors, both undoped and doped with rare earth elements Sm, Ce and Tb ions were synthesized using a solid-state method. The photoluminescent properties were investigated. For the Sr2EuAlO5 phosphor, the excitation spectra exhibited a broad charge transfer band ranging from 250 to 360 nm and some sharp peaks ranging from 450 to 550 nm, with the highest sharp peak at 463 nm. The emission spectra showed the red emission in both undoped and doped Sr2EuAlO5 phosphors, with the highest peak at 702 nm attributed to 5D0→7F4 transition under different excitation wavelengths of 393 and 463 nm. Doping Tb ions into the host lattice Sr2EuAlO5 resulted in an extraordinary ultra-high luminescence ratio of 5D0−7F4 at 702 nm to 5D0−7F2 at 620 nm, which was approximately three times higher than that of Sr2EuAlO5. Ce-doped Sr2EuAlO5 phosphors altered the shape of excitation spectra and charge transfer phenomenon was observed, while Sm-doped Sr2EuAlO5 significantly enhancing the emission intensity at 702 nm. In this study site preferential occupancy based on bond energy calculations was reported for the first time to theoretically confirm the dopant ion sites. The results indicate that Sm and Tb ions preferentially occupy the Eu1 sites, while Ce ions only occupied the Sr2 positions. The CIE values (x = 0.6311, y = 0.3512) and high color purity of 94.8 % in Sr2EuAlO5: 10 % Sm ions indicate its suitability as a red phosphor for WLEDs.
{"title":"Novel deep-red photoluminescence with extraordinary high luminescence ratio of 5D0−7F4 at 702 nm to 5D0−7F2 at 620 nm in Sr2EuAlO5","authors":"Muhammad Kamran , Chenglong Xia , Syeda Duaa Zahra , Xiao He, Bingyang Zeng, Chunmiao Cui, Jiahui Yang, Xiaoguang Liu, Ling Li","doi":"10.1016/j.jlumin.2024.120913","DOIUrl":"10.1016/j.jlumin.2024.120913","url":null,"abstract":"<div><div>A series of novel red-emitting Sr<sub>2</sub>EuAlO<sub>5</sub> phosphors, both undoped and doped with rare earth elements Sm, Ce and Tb ions were synthesized using a solid-state method. The photoluminescent properties were investigated. For the Sr<sub>2</sub>EuAlO<sub>5</sub> phosphor, the excitation spectra exhibited a broad charge transfer band ranging from 250 to 360 nm and some sharp peaks ranging from 450 to 550 nm, with the highest sharp peak at 463 nm. The emission spectra showed the red emission in both undoped and doped Sr<sub>2</sub>EuAlO<sub>5</sub> phosphors, with the highest peak at 702 nm attributed to <sup>5</sup>D<sub>0</sub>→<sup>7</sup>F<sub>4</sub> transition under different excitation wavelengths of 393 and 463 nm. Doping Tb ions into the host lattice Sr<sub>2</sub>EuAlO<sub>5</sub> resulted in an extraordinary ultra-high luminescence ratio of <sup>5</sup>D<sub>0</sub><sup>−7</sup>F<sub>4</sub> at 702 nm to <sup>5</sup>D<sub>0</sub><sup>−7</sup>F<sub>2</sub> at 620 nm, which was approximately three times higher than that of Sr<sub>2</sub>EuAlO<sub>5</sub>. Ce-doped Sr<sub>2</sub>EuAlO<sub>5</sub> phosphors altered the shape of excitation spectra and charge transfer phenomenon was observed, while Sm-doped Sr<sub>2</sub>EuAlO<sub>5</sub> significantly enhancing the emission intensity at 702 nm. In this study site preferential occupancy based on bond energy calculations was reported for the first time to theoretically confirm the dopant ion sites. The results indicate that Sm and Tb ions preferentially occupy the Eu1 sites, while Ce ions only occupied the Sr2 positions. The CIE values (x = 0.6311, y = 0.3512) and high color purity of 94.8 % in Sr<sub>2</sub>EuAlO<sub>5</sub>: 10 % Sm ions indicate its suitability as a red phosphor for WLEDs.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120913"},"PeriodicalIF":3.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359444","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 : 2024-09-26DOI: 10.1016/j.jlumin.2024.120918
Juanfang Zhou , Zimei Zhang , Meng Li , Yanpeng Lu , Defang Xu , Xingliang Liu
This study devotes to the design, preparation, and examination of two novel D-A structured molecules, designated as CCEDBF and BCCEDBF, which are derived from carbazole unit, dicyanoethylene segment, and dibenzofuran unit. The distinctive D-A molecular architectures and highly twisted spatial configurations of these compounds facilitate pronounced intramolecular charge transfer (ICT) while also imparting robust solid-state luminescence, exhibiting emission efficiencies of 0.518 and 0.739, respectively, and notable aggregation-induced emission (AIE) with AIE factors of 43 and 30. Significantly, both CCEDBF and BCCEDBF demonstrate reversible mechanofluorochromic (MFC) behavior characterized by high fluorescence contrast. Mechanical grinding of the initial powders results in a shift in their emission colors, transitioning from green and yellow-green to yellow and orange-red, respectively, alongside a corresponding shift in emission peaks from 525 nm to 536 nm–558 nm and 597 nm. Powder X-ray diffraction (PXRD) examination of the initially synthesized, mechanically processed, and vaporized samples reveals that the observed fluorescence color change is due to a structural transformation between ordered crystalline and disordered amorphous configurations induced by the application of the external force. The red shift in photoluminescence (PL) spectra post-grinding is attributed to a reduced band gap, driven by factors such as extended π-conjugation length, enhanced planar intramolecular charge transfer (PICT) effect, strengthened π-π interactions and exciton coupling, as well as the increase in the orbitals overlap between neighboring molecular. Moreover, the presence or absence of tert-butyl substituents attaching to the 3- and 6-positions of the carbazole units significantly impacts the photophysical properties of these materials.
{"title":"Design and synthesis of dicyanoethylene derivatives functionalized with carbazole possessing the properties of obvious aggregation-induced emission and reversible high-contrast mechanofluorochromism","authors":"Juanfang Zhou , Zimei Zhang , Meng Li , Yanpeng Lu , Defang Xu , Xingliang Liu","doi":"10.1016/j.jlumin.2024.120918","DOIUrl":"10.1016/j.jlumin.2024.120918","url":null,"abstract":"<div><div>This study devotes to the design, preparation, and examination of two novel D-A structured molecules, designated as <strong>CCEDBF</strong> and <strong>BCCEDBF</strong>, which are derived from carbazole unit, dicyanoethylene segment, and dibenzofuran unit. The distinctive D-A molecular architectures and highly twisted spatial configurations of these compounds facilitate pronounced intramolecular charge transfer (ICT) while also imparting robust solid-state luminescence, exhibiting emission efficiencies of 0.518 and 0.739, respectively, and notable aggregation-induced emission (AIE) with AIE factors of 43 and 30. Significantly, both <strong>CCEDBF</strong> and <strong>BCCEDBF</strong> demonstrate reversible mechanofluorochromic (MFC) behavior characterized by high fluorescence contrast. Mechanical grinding of the initial powders results in a shift in their emission colors, transitioning from green and yellow-green to yellow and orange-red, respectively, alongside a corresponding shift in emission peaks from 525 nm to 536 nm–558 nm and 597 nm. Powder X-ray diffraction (PXRD) examination of the initially synthesized, mechanically processed, and vaporized samples reveals that the observed fluorescence color change is due to a structural transformation between ordered crystalline and disordered amorphous configurations induced by the application of the external force. The red shift in photoluminescence (PL) spectra post-grinding is attributed to a reduced band gap, driven by factors such as extended π-conjugation length, enhanced planar intramolecular charge transfer (PICT) effect, strengthened π-π interactions and exciton coupling, as well as the increase in the orbitals overlap between neighboring molecular. Moreover, the presence or absence of <em>tert</em>-butyl substituents attaching to the 3- and 6-positions of the carbazole units significantly impacts the photophysical properties of these materials.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120918"},"PeriodicalIF":3.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423548","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}
Novel functional materials that integrate multiple tunable luminescence modes hold significant scientific and application potential. In this study, nanostructure strategies were employed to fabricate a series of microcrystalline glasses doped with rare-earth and transition-metal ions. The crystallization behavior of the nanocrystals (NCs) was revealed through high-resolution transmission electron microscopy (HRTEM), and the photoluminescence spectra of the samples were systematically investigated, demonstrating the achievement of independent and efficient visible light emission. With the further addition of the dopant Mn2+, it can occupy different sites to generate efficient energy transfer for ions, effectively improve the luminous efficiency, and changing the Mn2+ concentration can achieve a wide tunable color gamut. In addition, by exciting the glass samples with different excitation light sources, tunable emission of both red and blue was achieved. The results demonstrated the significant potential of the experimental samples as new multifunctional materials for optical dynamic anti-counterfeiting applications.
{"title":"Controllable multicolored optical glass-ceramics based on nanostructure strategies and dopants","authors":"Junyi Wang, Feifei Huang, Guoqing Jiang, Ruoshan Lei, Denghao Li, Shiqing Xu","doi":"10.1016/j.jlumin.2024.120917","DOIUrl":"10.1016/j.jlumin.2024.120917","url":null,"abstract":"<div><div>Novel functional materials that integrate multiple tunable luminescence modes hold significant scientific and application potential. In this study, nanostructure strategies were employed to fabricate a series of microcrystalline glasses doped with rare-earth and transition-metal ions. The crystallization behavior of the nanocrystals (NCs) was revealed through high-resolution transmission electron microscopy (HRTEM), and the photoluminescence spectra of the samples were systematically investigated, demonstrating the achievement of independent and efficient visible light emission. With the further addition of the dopant Mn<sup>2+</sup>, it can occupy different sites to generate efficient energy transfer for ions, effectively improve the luminous efficiency, and changing the Mn<sup>2+</sup> concentration can achieve a wide tunable color gamut. In addition, by exciting the glass samples with different excitation light sources, tunable emission of both red and blue was achieved. The results demonstrated the significant potential of the experimental samples as new multifunctional materials for optical dynamic anti-counterfeiting applications.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120917"},"PeriodicalIF":3.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327866","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 structural, morphological, linear, and nonlinear optical properties of Cr2O3 thin films with different thicknesses deposited by the thermal deposition, were measured. The structural and morphological parameters of films, determined by XRD, FESEM, and AFM images, are compared to the linear and nonlinear optical characteristics of these media. The bandgap of prepared thin films was obtained from DRS spectra. The electron effective mass (), linear refractive index (), optical static, and high frequency dielectric constant ( , ) values were calculated by using the band gap energy values. Increasing the thicknesses of thin films causes to decrease the band gap, an increase RMS, increase the size of nanoparticles and the nonlinear responses of thin films. The high magnitude of n2, and β belonged to the Cr2O3 (300 nm-thickness) in the order of 10−5 cm2/W, and 10−1 cm/W respectively. The fluctuations in nonlinear responses observed at different thicknesses are attributed to d-d transitions and intraband scattering of equilibrium electrons influenced by laser radiation, as indicated by the nonlinearity data. The considerably elevated refractive non-linearity values in the analyzed film materials suggest their potential for practical applications in optoelectronic devices.
{"title":"Influence of d-d transition electrons and thickness variations on the excited-state optical properties: Nonlinear optical characterization of Cr2O3 thin film","authors":"Ammar S. Alattar , Marzieh Nadafan , Zahra Dehghani , Morteza Khashehchi","doi":"10.1016/j.jlumin.2024.120916","DOIUrl":"10.1016/j.jlumin.2024.120916","url":null,"abstract":"<div><div>The structural, morphological, linear, and nonlinear optical properties of Cr<sub>2</sub>O<sub>3</sub> thin films with different thicknesses deposited by the thermal deposition, were measured. The structural and morphological parameters of films, determined by XRD, FESEM, and AFM images, are compared to the linear and nonlinear optical characteristics of these media. The bandgap of prepared thin films was obtained from DRS spectra. The electron effective mass (<span><math><mrow><msubsup><mi>m</mi><mi>e</mi><mo>∗</mo></msubsup><mo>/</mo><msub><mi>m</mi><mn>0</mn></msub></mrow></math></span>), linear refractive index (<span><math><mrow><msub><mi>n</mi><mn>0</mn></msub></mrow></math></span>), optical static, and high frequency dielectric constant (<span><math><mrow><msub><mi>ε</mi><mn>0</mn></msub></mrow></math></span> , <span><math><mrow><msub><mi>ε</mi><mi>∞</mi></msub></mrow></math></span>) values were calculated by using the band gap energy values. Increasing the thicknesses of thin films causes to decrease the band gap, an increase RMS, increase the size of nanoparticles and the nonlinear responses of thin films. The high magnitude of n<sub>2</sub>, and β belonged to the Cr<sub>2</sub>O<sub>3</sub> (300 nm-thickness) in the order of 10<sup>−5</sup> cm<sup>2</sup>/W, and 10<sup>−1</sup> cm/W respectively. The fluctuations in nonlinear responses observed at different thicknesses are attributed to d-d transitions and intraband scattering of equilibrium electrons influenced by laser radiation, as indicated by the nonlinearity data. The considerably elevated refractive non-linearity values in the analyzed film materials suggest their potential for practical applications in optoelectronic devices.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"277 ","pages":"Article 120916"},"PeriodicalIF":3.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359443","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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