Journal of Luminescence最新文献

{"title":"Radiative transitions in irradiated MgAl2O4 spinel crystal","authors":"L. Museur ,&nbsp;E. Feldbach ,&nbsp;Y. Smortsova ,&nbsp;A. Kotlov ,&nbsp;A. Kanaev","doi":"10.1016/j.jlumin.2024.121029","DOIUrl":"10.1016/j.jlumin.2024.121029","url":null,"abstract":"<div><div>Radiative transitions in MgAl₂O₄ spinel single crystal were investigated after irradiation with He⁺ ions of fluence ∼10¹⁷ particles/cm². Photoluminescence (PL), PL excitation spectra and PL decay curves were measured at cryogenic temperatures of 8 K. It is shown that PL decay kinetics of 5 eV (250 nm) and 3 eV (420 nm) bands are similar because of the common excited state. Furthermore, after irradiation PL band at ∼5 eV preserved characteristic behaviour of the donor-acceptor pair transitions. The PL channels involve electronic transitions of antisite defects, Mg_Al (shallow acceptor) and Al_Mg (shallow donor), and oxygen vacancy V_O (deep donor), while Al_Mg served an intermediate of the electronic excitation channel. The intense emissions were assigned to V_O^•∗ → V_O^• (3 eV) and V_O^•∗ → Mg_Al^× (5 eV), which involve respectively energy and energy-electron transfer. Participation of the doubly-ionized oxygen vacancy V_O^•• in the energy/electron transfer is suggested. The obtained data enabled a generalised scheme of electronic transitions in MgAl₂O₄ spinel in presence of intrinsic defects.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"279 ","pages":"Article 121029"},"PeriodicalIF":3.3,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Great improvement in intensity and thermal stability of Ca9Ga(XO4)7: Cr3+ near-infrared photoluminescence by next nearest coordination substitution","authors":"Shifang Wang ,&nbsp;Mingzheng Sun ,&nbsp;Xiaolang Fan ,&nbsp;Bowei Liu ,&nbsp;Chuangchuang Qiao ,&nbsp;Shuang Jing ,&nbsp;Xufeng Zhou ,&nbsp;Wei Li ,&nbsp;Yangbo Wang ,&nbsp;Huaiyong Li","doi":"10.1016/j.jlumin.2024.121028","DOIUrl":"10.1016/j.jlumin.2024.121028","url":null,"abstract":"<div><div>Broad band near-infrared emitting phosphors activated with Cr³⁺ ions have great potential in a variety of applications. The luminescence efficiency and thermal stability are two critical parameters that are highly concerned in practical applications. In this work, a series of Cr³⁺ ion-activated Ca₉Ga(PO₄)_x(VO₄)_7-x were synthesized. The photoluminescence (PL) properties of Cr³⁺ were studied as functions of coordination environment, Cr³⁺ concentration and temperature. The coordination environment of Cr³⁺ ions is modified by gradually substitution of P by V without change the crystal structure of the host lattice. A continuous solid solution is formed, and the cell parameters and volume increase monotonically with V content. Great improvement in the intensity is observed for Ca₉Ga(PO₄)_3.5(VO₄)_3.5, which increases by 26 and 2.4 times than the parents compositions Ca₉Ga(PO₄)₇ and Ca₉Ga(VO₄)₇, respectively. Decay dynamic analysis suggests that both coordination environment modification and reduction of quenching center responsible for the great enhancement. An optimized concentration of 3.0 % is revealed and the intensity at 433 K maintains 81.1 % of the intensity at 293 K, respectively.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"279 ","pages":"Article 121028"},"PeriodicalIF":3.3,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145290","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}

{"title":"High color-purity (λem = 845 nm) near-infrared (NIR) polymer light-emitting diode (PLED) based on one [ir(C^N)2(N^O)]-bis-heteroleptic Ir(III)-complex","authors":"Yan Zhang ,&nbsp;Youquan Chen ,&nbsp;Tiendrebeogo Salamata,&nbsp;Sicheng Yao,&nbsp;Xingqiang Lü,&nbsp;Guorui Fu,&nbsp;Haixia Ma","doi":"10.1016/j.jlumin.2024.121025","DOIUrl":"10.1016/j.jlumin.2024.121025","url":null,"abstract":"<div><div>The development of efficient color-purity near-infrared iridium(III) complexes with emission beyond 800 nm is extremely challenging. Herein, we report a new [Ir(C^N)₂(N^O)]-<em>bis</em>-heteroleptic Ir(III)-complex <strong>[Ir(tbpz)</strong>_{<strong>2</strong>}<strong>(L)]</strong> using <strong>Htbpz</strong> (tribenzo[<em>a,c,i</em>]phenazine) as the highly conjugated HC^N main ligand and <strong>HL</strong> ((E)-2-(phenylimino)methyl)phenol) as the N^OH ancillary ligand. The photophysical result of <strong>[Ir(tbpz)</strong>_{<strong>2</strong>}<strong>(L)]</strong> demonstrates that its color-purity narrowband (<em>λ</em>_em = 835 nm; <em>Φ</em>_PL = 1.9 %) NIR-emission with a FWHM (full width at half maximum) of 45 nm is arisen from the ³ILCT-dominant (ILCT = intraligand charge transfer) T₁ state. The solution-processed NIR-PLEDs based on <strong>[Ir(tbpz)</strong>_{<strong>2</strong>}<strong>(L)]</strong> could achieve the desirable color-purity NIR-emission peaking at 845 nm with the <em>η</em>_EQE^Max values of 0.18–0.33 %.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"279 ","pages":"Article 121025"},"PeriodicalIF":3.3,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144759","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}

{"title":"Ultrafast dynamics modulated by the number of central metal protons in 3d-orbitals metal complexes","authors":"Haixia Zhu ,&nbsp;Zhaozhe Chen ,&nbsp;Jun Li,&nbsp;Zhihui Chen ,&nbsp;Si Xiao","doi":"10.1016/j.jlumin.2024.121005","DOIUrl":"10.1016/j.jlumin.2024.121005","url":null,"abstract":"<div><div>The lability of metal center, Jahn-Telller distortions, and structure-dependent energetics could influence the excited state dynamics of transition metal complexes to affect their application in photochemistry field. In this work, Co, Ni, and Cu-complexes, whose belong to 3d-orbitals metal complexes, are investigated by the time-resolved transient absorption (TA) spectrum upon 325 nm laser excitation. Their excited state dynamic shows the photobleaching in ultraviolet band and photoinduced absorption response in visible band. Compared to the ligand, the relaxation time at 350 nm remains in the range of 5.5 ps–9.4 ps, while a new fast relaxation appears as 160–290 fs at 450 nm. It is attributed to the intersystem crossing (ISC) from the ¹MLCT state to the ³MLCT state transitions, which is side proofed by the decreasing lifetimes as the increasing numbers of shell electrons in central metal. This mechanism could be results in saturable absorption in ultraviolet band and reverse saturable absorption in visible band, which was confirmed by the Z-scan experiments. These finding provide insight into the photophysical mechanisms in 3d-metal-based complexes.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"278 ","pages":"Article 121005"},"PeriodicalIF":3.3,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166756","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}

{"title":"Dual-mode optical thermometry via efficient Bi3+→Eu3+ energy transfer in CaScAlSiO6 phosphors","authors":"Zhixian Zhang ,&nbsp;Qingfeng Guo ,&nbsp;Pengfei Shuai ,&nbsp;Ke Su ,&nbsp;Lefu Mei ,&nbsp;Libing Liao","doi":"10.1016/j.jlumin.2024.121026","DOIUrl":"10.1016/j.jlumin.2024.121026","url":null,"abstract":"<div><div>Accurate and self-referential temperature measurements are crucial for monitoring inaccessible workpieces, hazardous environments, and fluids. In this study, we developed CaScAlSiO₆:Bi³⁺/Eu³⁺, a high-sensitivity, polychromatic, dual-luminescent center optical thermometric material, and investigated its luminescence mechanism through emission spectroscopy and decay lifetime characterization. By adjusting the Bi³⁺ to Eu³⁺ ratio, the samples achieved a visible color transition from blue to pink, revealing a unique energy transfer mechanism between the two luminescent centers that enables tunable emission and enhanced sensitivity. Owing to the unique thermal quenching characteristics of Bi³⁺ and Eu³⁺, the CaScAlSiO₆ samples demonstrated superior optical thermometry capabilities over a temperature range from 323 K to 453 K. At 453 K, the fluorescence intensity ratio between Bi³⁺ and Eu³⁺ reached peak sensitivities, absolute sensitivity (S_a) of 4.11 % K⁻¹ and relative sensitivity (S_r) of 0.87 % K⁻¹. Additionally, these samples exhibited a significant chromatic shift of 0.0508, demonstrating the potential for visual temperature sensing, while consistently showing excellent reversibility and repeatability in performance. The impressive performance of the two temperature measurement systems, characterized by their exceptional results, high sensitivity, and precise signal resolution, positions CaScAlSiO₆:Bi³⁺/Eu³⁺ luminescent materials as a promising candidate for multi-mode and self-referenced luminescent thermometry applications.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"279 ","pages":"Article 121026"},"PeriodicalIF":3.3,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145250","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}

{"title":"Prediction and exploration of emission wavelength (or energy) of luminescent materials based on machine learning","authors":"Xin Shi ,&nbsp;Xiaotong Zhong ,&nbsp;Wei Liu ,&nbsp;Songwei Wang ,&nbsp;Zhijun Zhang ,&nbsp;Li Lin ,&nbsp;Yuguo Chen ,&nbsp;Kehong Zhang ,&nbsp;Jingtai Zhao","doi":"10.1016/j.jlumin.2024.121024","DOIUrl":"10.1016/j.jlumin.2024.121024","url":null,"abstract":"<div><div>In the optical field of materials science, it is important to predict the emission wavelength (or energy) of luminescent materials, especially when different dopant ions are involved, which makes the investigation even more complex. The selection of doped ions directly determines the optical properties of luminescent materials, so the accurate prediction of the emission wavelength (or energy) of doped luminescent materials has become a key challenge in scientific research. Traditional theoretical calculation methods often fail to fully consider the complexity of the interactions between ions in different material systems, but machine learning models provide an efficient solution for the research in this field. In this study, we collected a large amount of data of light-emitting materials doped with different ions, combined with their structural feature descriptors, and used a variety of machine learning models to predict the emission wavelength. On the basis of this model we give a prediction of the emission wavelength of the actually synthesized luminous materials in our research group, which are more accurate in the quality of luminous materials doped with Eu^3+, Sm³⁺ plus some Tb³⁺ ions. In the further analysis of the factors affecting the emission wavelength (or energy) of the luminescent materials, we find that the mean first ionization potential, the mean electron affinity and the mean Pauling electronegativity are the key factors. This study shows that machine learning methods have great application potential in wavelength (or energy) prediction of luminous materials and provide an effective tool for material screening and performance optimization in the future.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"279 ","pages":"Article 121024"},"PeriodicalIF":3.3,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144757","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}

{"title":"Sub-bandgap laser-induced fluorescence in the CaF2 via a linear process","authors":"Mariem Guesmi ,&nbsp;Tomáš Thoř ,&nbsp;František Procháska ,&nbsp;Martina Hlubučková ,&nbsp;Vít Kanclíř ,&nbsp;Oumayma Taboubi ,&nbsp;Ivana Šeděnková ,&nbsp;Karel Žídek","doi":"10.1016/j.jlumin.2024.121023","DOIUrl":"10.1016/j.jlumin.2024.121023","url":null,"abstract":"<div><div>Calcium fluoride (CaF₂) is an excellent material for deep-ultraviolet optics. However, exposure to intense UV laser light can induce new defects in the material, a phenomenon known as laser-induced fluorescence (LIF). In our study, a femtosecond laser with a wavelength of 257 nm (4.82 eV, i.e., below CaF₂ bandgap) was used to induce the LIF. We thoroughly studied the phenomenon behind the photoluminescence (PL) and its variation. Based on its linear excitation intensity dependence, we assigned the PL below 3.4 eV to sub-bandgap defect emission. The rate of LIF in this spectral region also scaled linearly with the irradiation pulse intensity. At the same time, the LIF rate was strongly dependent on the repetition rate. Our results suggest that laser-induced heating is responsible for the observed PL changes. We rationalized our observations based on the formation of F- and M-centres in CaF₂.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"278 ","pages":"Article 121023"},"PeriodicalIF":3.3,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166807","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}

{"title":"Scintillation properties of SrCl2:Eu transparent ceramics fabricated by spark plasma sintering method","authors":"Takeshi Ubukata,&nbsp;Shota Otake,&nbsp;Takumi Kato,&nbsp;Daisuke Nakauchi,&nbsp;Noriaki Kawaguchi,&nbsp;Takayuki Yanagida","doi":"10.1016/j.jlumin.2024.121021","DOIUrl":"10.1016/j.jlumin.2024.121021","url":null,"abstract":"<div><div>In this report, SrCl₂:Eu transparent ceramics were fabricated by the spark plasma sintering method, and their optical and scintillation properties were investigated. All the samples exhibited the photoluminescence (PL) and scintillation emission peaks at 410 nm derived from the 5d–4f transitions of Eu²⁺. The PL quantum yields of the 0.1, 0.25, 0.5, and 1.0 % SrCl₂:Eu samples under 340 nm excitation were 50, 78, 88, and 81 %, respectively. The scintillation decay curves were approximated by a single exponential decay function with decay time constants of 920–1010 ns. The scintillation light yield under ¹³⁷Cs γ-ray irradiation was the highest for the 0.5 % Eu sample with 24,000 ph/MeV.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"278 ","pages":"Article 121021"},"PeriodicalIF":3.3,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166757","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}

{"title":"Role of dopant concentration and starting reagents in the dosimetric performance of MgB4O7:Ce,Li","authors":"Igor Plokhikh ,&nbsp;Ilia I. Sadykov ,&nbsp;Olga V. Safonova ,&nbsp;Łukasz Kondracki ,&nbsp;Eduardo G. Yukihara ,&nbsp;Lily Bossin ,&nbsp;Dariusz Jakub Gawryluk","doi":"10.1016/j.jlumin.2024.121019","DOIUrl":"10.1016/j.jlumin.2024.121019","url":null,"abstract":"<div><div>MgB₄O₇:Ce,Li has emerged as a promising candidate for optically stimulated luminescence dosimetry (OSL) due to its high sensitivity to ionizing radiation, fast luminescence, and extended linear dose-response range. Despite its potential, variations in fading behavior and discrepancies in the linear dose-response region reported in the literature, compounded by a lack of direct sensitivity comparisons across studies, have raised questions regarding the reproducibility of the synthesis. These inconsistencies are believed to stem from differing synthesis methods. Our study integrates X-ray diffraction, synchrotron X-ray absorption spectroscopy, and comprehensive thermoluminescent (TL) and OSL analyses to demonstrate that the choice of starting reagents, and not the synthetic treatment per se, is critical for optimizing the dosimetric properties of MgB₄O₇:Ce,Li. Specifically, we find that using nitrates of Mg, Li, and Ce as precursors enhances the luminescent intensity compared to preparations from their respective oxides. This can be attributed to a more efficient incorporation of Ce³⁺ into the MgB₄O₇ lattice, contrary to the case of oxide precursors, where segregation of CeO₂ takes place. Our findings, alongside previous reports, pinpoint two pivotal factors in modulating the properties of MgB₄O₇:Ce,Li: sample preparation temperature and effective cerium concentration within the material.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"279 ","pages":"Article 121019"},"PeriodicalIF":3.3,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intensity and optical resetting of Infrared Photoluminescence (IRPL) and Infrared Stimulated Luminescence (IRSL) signals in feldspars","authors":"J.A. Winzar ,&nbsp;G.A.T. Duller ,&nbsp;H.M. Roberts ,&nbsp;M. Gunn ,&nbsp;A.M.T. Bell","doi":"10.1016/j.jlumin.2024.121018","DOIUrl":"10.1016/j.jlumin.2024.121018","url":null,"abstract":"<div><div>Feldspars vary in major and minor element chemistry and mineral structure. For luminescence dating, separating feldspar types in sediments using density separation techniques is challenging, and when using rock slices and fine-grain samples it is not possible. For 19 chemically and structurally diverse feldspars, the intensity and optical resetting behaviour of different Infrared Photoluminescence (IRPL) and Infrared Stimulated Luminescence (IRSL) signals is investigated. After a 140 Gy beta dose IRPL was observed from each feldspar, and IRSL signals were seen in all except the most Ca-rich sample. The intensity of IRPL was more strongly related to feldspar major element chemistry than appeared to be the case for IRSL signals, where some K-rich and K-poor feldspars have similar IRSL intensities. Correlations between Fe and Mn concentrations with IRSL and IRPL signal intensity were found. The influence of mineral structure, particularly the state of Al,Si order also appeared to affect IRSL intensity.</div><div>Bleaching experiments showed that IRPL signals are more difficult to bleach in comparison to IRSL. In some K-rich and K-poor feldspars resetting of IRPL was limited, and an IRPL component with lower optical sensitivity was observed in each IRPL signal. The IRPL signal remaining after subtracting this component, and also delta IRPL (ΔIRPL) signals, bleach in a similar manner to IRSL signals measured at elevated temperatures (225 and 290 °C). IRSL bleached reproducibly across the samples, with most IRSL₅₀ and pIR₅₀ IRSL₂₂₅ signals decreasing to below 5% of the initial signal intensity after ∼1000 s and ∼10,000 s, respectively. A relationship was seen between IRPL bleaching and Ca-content, but no clear trends were observed between bleaching and Na and K contents, or minor element chemistry and mineral structure. This study shows that the suitability of IRPL signals for dating in terms of their potential to be effectively bleached in nature can be enhanced by subtracting the less optically sensitive component from the signals used.</div></div>","PeriodicalId":16159,"journal":{"name":"Journal of Luminescence","volume":"278 ","pages":"Article 121018"},"PeriodicalIF":3.3,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143166755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}