Optical Materials最新文献

{"title":"Band gap values and structural changes on MoO3 obtained by ion-exchange method","authors":"P.H. Silva,&nbsp;D.T. Cestarolli,&nbsp;E.M. Guerra","doi":"10.1016/j.optmat.2025.117063","DOIUrl":"10.1016/j.optmat.2025.117063","url":null,"abstract":"<div><div>In this work we present a study of a new synthesis for molybdenum oxide (MoO₃) produced by an ion-exchange method in the sol-gel route as well as its structural characterization. Subsequently, the influences of this new synthesis under the structure and, consequently, its optical properties have been examined. Different pH and concentration values were used: pH = 2, 4 and 5; and concentrations: 0.05, 0.10, 0.20, 0.30, 0.40 and 0.50 mol L⁻¹. From the X-ray diffraction profiles, the presence of two polymorphic phases of MoO₃ were observed: the stable phase <em>α</em>-MoO₃ in its orthorhombic form and the metastable phase <em>h</em>-MoO₃ which corresponds to its hexagonal structure. In the spectroscopic investigation, by adopting Tauc's plot, the optical band gap energies of MoO₃ are estimated. The band gap widening from 2.58 to 3.99 eV, which were useful in the energetic evaluation of electron transfer between the conduction and valence bands between oxygen and molybdenum, also confirms the effect of structure variation, further confirming the effect of the structural variations induced by the new synthesis method in different conditions.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117063"},"PeriodicalIF":3.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Excitation varying of Pr3+ ion emission stimulated by annealing in Si-rich HfO2:Pr films prepared by magnetron sputtering","authors":"T. Torchynska ,&nbsp;Jose Oliveros Garcia ,&nbsp;Jose Luis Casas Espinola ,&nbsp;Leonardo Gabriel Vega Macotela ,&nbsp;Luis Lartundo Rojas ,&nbsp;L. Khomenkova ,&nbsp;F. Gourbilleau","doi":"10.1016/j.optmat.2025.117066","DOIUrl":"10.1016/j.optmat.2025.117066","url":null,"abstract":"<div><div>The impact of high temperature annealing at 800–1100 °C on photoluminescence (PL) via 4f shell levels of Pr³⁺ions, as well as peculiarities of their excitation in Si-rich HfO₂:Pr films prepared by magnetron spattering are studied. Efficient oxidation and crystallization of Si-HfO₂:Pr films with the appearance of tetragonal HfO₂ crystalline phase after annealing at 1000 °C are revealed, which are accompanied by the increase of oxygen content in the films and dissolution of Si quantum dot (QD) inclusions. Simultaneously, efficient PL emissions connected with optical transitions in the 4f energy levels of Pr³⁺ions are detected. It has been shown that in highly oxidized films annealed at 1000 °C, the PL excitation of low energy PL bands in the 4f shell of Pr³⁺ions dominates. The latter is due to the involvement in the excitation of Pr³⁺ion emission of oxygen related defects (interstitial O_i atoms and molecules). On the contrary, upon annealing at 1100 °C, the content of oxygen atoms in the films decreases together with the generation of oxygen vacancies. This latter conclusion was confirmed by the analysis of the variable signals of Si2p, Hf4f, O1s and Pr3d in the high-resolution X-ray photoelectron spectra (HR-XPS) of the films. Moreover, the appearance of oxygen vacancies upon annealing at 1100 °C stimulates the drastic variation of the PL spectra of Pr³⁺ions due to the change of dominated defects, which participate in the excitation of Pr³⁺ion emission. In the latter case, the excitation of high energy PL bands in the 4f shell of Pr³⁺ions occurs with the excitation energy transfer through O vacancies. The results obtained are important for applications of HfO₂:Pr films in telecommunication technology.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117066"},"PeriodicalIF":3.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth of high-quality, large-size CsI and CsI(Tl) scintillator single crystals via continuous-mass transport process method","authors":"Hongyi Yang ,&nbsp;Ziyi Lai ,&nbsp;Wenzhen Wang ,&nbsp;Huanzhen Qi ,&nbsp;Shaohan Wang ,&nbsp;Junfeng Chen ,&nbsp;Juan Qin ,&nbsp;Hui Zhang ,&nbsp;Zebo Fang ,&nbsp;Haitao Xu ,&nbsp;Run Xu ,&nbsp;Yan Zhu","doi":"10.1016/j.optmat.2025.117065","DOIUrl":"10.1016/j.optmat.2025.117065","url":null,"abstract":"<div><div>Cesium iodide crystals with large sizes are highly desirable for X-ray and γ-ray detection applications. In this study, we have designed a simple and convenient continuous-mass transport process (CMTP) method to obtain large-size, high-quality pure CsI and Tl doped CsI crystals for the first time. This method allows for a continuous replenishment of the raw materials required for crystal growth in the growth container through a solute diff usion process, facilitating the stable growth of large single crystals (up to a size of 23.5 × 21 × 8 mm³). Furthermore, by adjusting the temperature difference between the growth and supplement containers, it is feasible to control the crystal growth rate. Compared with the inverse temperature crystallization (ITC) method, Tl doped CsI crystals grown by the CMTP method exhibit better crystallization quality, with both smaller values and narrower fluctuations for full width at half maximum (FWHM) in the X-ray rocking curve, and achieve comparable energy resolution (6.20 %–6.73 %), decay time (649–657 ns), afterglow level (0.1 % @ 68–98 ms), and higher light yield (78,000–83,000 photons/MeV). Our work provides a promising strategy for the preparation of larger-sized Tl doped CsI single crystals via the CMTP method.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117065"},"PeriodicalIF":3.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermally induced transformation of “dark” precursors into laser-active centers: Hidden potential of bismuth-doped fibers","authors":"A.V. Kharakhordin ,&nbsp;S.V. Alyshev ,&nbsp;A.A. Umnikov ,&nbsp;D.I. Oleinik ,&nbsp;E.G. Firstova ,&nbsp;A.M. Khegai ,&nbsp;A.V. Elopov ,&nbsp;M.A. Melkumov ,&nbsp;S.V. Firstov","doi":"10.1016/j.optmat.2025.117025","DOIUrl":"10.1016/j.optmat.2025.117025","url":null,"abstract":"<div><div>This paper presents a comprehensive study of the transformation of “dark” (undetected with UV–IR spectroscopy) precursors into bismuth active centers (BACs) associated with Si atoms during thermal treatment, which can be considered as an assessment of the upper limit of Bi-doped fibers in terms of maximum achievable gain and as search for ways to improve their optical characteristics. This concept is based on the study of various bismuth-related forms in active media and the possible processes of their transformations, which, in essence, determines its “hidden” potential. Using Bi-doped low-GeO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>-SiO₂ glass fibers it was established that the proposed concept allows us to give a generalized assessment of the prospects of fiber design, as well as to optimize the chemical composition and corresponding technological conditions for their manufacturing. We show that the fraction of Bi ions forming BACs can reach 90% in the best fibers after efficient conversion induced by thermal treatment, while the pristine fibers contain only 30% of Bi ions in BACs and <span><math><mo>∼</mo></math></span>60% in “dark” precursors. It was experimentally found that physicochemical reaction of ”dark” precursors <span><math><mo>→</mo></math></span> BACs is characterized by an activation energy of <span><math><mo>∼</mo></math></span>2.1 eV and a rate constant of 10<span><math><msup><mrow></mrow><mrow><mn>7</mn></mrow></msup></math></span> s⁻¹. In addition, more information on Bi-related centers responsible for unsaturable loss was obtained. This approach showed that optical characterization of the initial state of the active medium, particularly the bismuth-doped GeO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>-SiO₂ fibers, is not always decisive for determining its potential.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117025"},"PeriodicalIF":3.8,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A machine learning-quantum chemical quest to predict the photovoltaic properties of 2D molybdenum sulfide super structures","authors":"Abrar U. Hassan ,&nbsp;Mamduh J. Aljaafreh","doi":"10.1016/j.optmat.2025.117056","DOIUrl":"10.1016/j.optmat.2025.117056","url":null,"abstract":"<div><div>The current study introduces a machine learning (ML)-driven method to forecast the photovoltaic (PV) characteristics of two-dimensional (2D) molybdenum sulfide (MoS) superstructures. Structural data of about 1202 compounds is compiled and four top performing models are trained to predict their open-circuit voltage (V_oc). The models are evaluated by using their mean squared errors (MSE), which spanned from 0.47 to 1.23, reflecting adequate predictive accuracy. Their stability evaluations are determined via their tolerance factor which reveals a significant relationship with both V_oc. Moreover, the materials with its optical properties are confirmed using the Kramers-Kronig relations, displaying a high level of consistency between experimental data and simulated results. The SHapley Additive exPlanations (SHAP) analysis identifies that their polarizability (Alpha) and first order connectivity (chi1) are the most important factors to affect their model performance. The bandgaps of MoS₂ and MoS₃₃ are calculated as 1.47 and 0.72 eV, respectively. These results can enhance the understanding of the PV potential of MoS based 2D materials and can lay the foundation for further studies in this field.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117056"},"PeriodicalIF":3.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Z-scheme based fabrication of Cu2CdSnS4/Au/g-C3N4 ternary heterojunction with enhanced photocatalytic hydrogen production","authors":"Saravanan Kamalakannan ,&nbsp;Natarajan Balasubramaniyan ,&nbsp;Bernaurdshaw Neppolian","doi":"10.1016/j.optmat.2025.117051","DOIUrl":"10.1016/j.optmat.2025.117051","url":null,"abstract":"<div><div>Using the photo-deposition-hydrothermal approach, we synthesized a new Z-scheme Cu₂CdSnS₄/Au/g-C₃N₄ ternary heterojunction with varying levels of Au. This was done to improve the photocatalytic performance of the material. Due to rapid electron-hole recombination and insufficient solar light absorption, Cu₂CdSnS₄/Au/g-C₃N₄ struggles to achieve its maximum photocatalytic activity. Cu₂CdSnS₄/Au/g-C₃N₄ heterojunction photocatalysts, which are composed of nanosheets of Au/g-C₃N₄ and Cu₂CdSnS₄, have recently been studied by employing several techniques. These hybrid photocatalysts are characterized by their heterojunction properties. A variety of methods may be utilized, including SEM, XRD, FT-IR, XPS, TEM, and UV–Vis. After 3 h under visible light irradiation, it was discovered that the final composite Cu₂CdSnS₄/Au/g-C₃N₄ heterojunction generated 2478.6 μmol g⁻¹ hydrogen. This result was 14 times greater than the pristine g-C₃N₄ heterojunction and 4.5 times greater than the pristine Cu₂CdSnS₄ heterojunction. On the other hand, the sacrificial electron donors triethanolamine (TEOA) and methanol exhibited extended photostability, with hydrogen production rates of 2478.6 μmol g⁻¹ and 330.7 μmol g⁻¹, respectively, compared to glycerol, which yielded a hydrogen production rate of 2105.7 μmol g⁻¹. After conducting an in-depth investigation of heterojunction photocatalysts, we found that Cu₂CdSnS₄ is highly effective in photon harvesting. This efficiency is attributed to the selective utilization of Z-scheme charge transfer, enabled by multiple charge transfer pathways. This study confirmed that heterojunction photocatalysts exhibit outstanding photocatalytic performance for hydrogen production.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117051"},"PeriodicalIF":3.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement the optoelectronic properties of chitosan biopolymer using natural dye of black olive as a novel approach: FTIR, XRD and UV–vis spectroscopic studies","authors":"Dyari Mustafa Mamad ,&nbsp;Dana S. Muhammad ,&nbsp;Shujahadeen B. Aziz ,&nbsp;Daron Q. Muheddin ,&nbsp;Bahez Y. Ahmed ,&nbsp;Karzan A. Abdalkarim ,&nbsp;Bandar A. Al-Asbahi ,&nbsp;Abdullah A.A. Ahmed ,&nbsp;Omed Gh Abdullah","doi":"10.1016/j.optmat.2025.117057","DOIUrl":"10.1016/j.optmat.2025.117057","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The current study brings new knowledge about the role of natural waste dyes in modifying the optoelectronic properties of biodegradable polymers. The black olive dyes (BODs) were extracted using distilled water. Solution cast technique was used to fabricate Chitosan (CS) CS:BOD films with enhanced absorption character. The extracted BODs were examined using FTIR routine to identify functional groups such as OH/NH, C&lt;img&gt;O, CH, and CH&lt;sub&gt;2&lt;/sub&gt;. The bands observed in FTIR spectra of CS:BOD films confirmed the existence of huge functional groups in the BODs. X-ray diffraction (XRD) analysis revealed that doping CS with BOD leads to change in structure and the regular molecular arrangement in CS. UV–vis spectra of pure BODs and pure CS were compared. The UV–vis spectra CS:BOD films reveal increased absorption while transmittance decreased. The absorption edge shifted to lower photon energy, and the Urbach energy was used to calculate the steepness (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) and of the electron-phonon interaction (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mtext&gt;ph&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) parameters. The refractive index and the angle of refraction of the rays emitted from the film's backside were studied. Various models correlating the energy gap to calculate the refractive index were investigated. The optical spectral moments &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; have been determined utilizing the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; values obtained from the Wemple-DiDomenico (W-D) model. Optical dielectric loss, the Tauc model, and the absorption spectrum fitting (ASF) strategy were used to determine the optical band gap and specify the dominant type of transition associated with transition electrons. The values in eV for damping frequency (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), plasma energy (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;ψ&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), valence electron plasma energy (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;mi&gt;p&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;), Penn energy, and Fermi energy (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) were determined. The sheet resistance (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) and the thermal emissivity (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;ε&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) were determined with the help of refractive index and transmittance parameters. The figure of the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mi&gt;φ&lt;/mi&gt;&lt;mtext&gt;film&lt;/mtext&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; parameter is clearly used to distinguish the optical properties of the pure polymer in comparison to that of the","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117057"},"PeriodicalIF":3.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SnSe2/TiO2 heterostructures for broadband photodetection","authors":"Kuri Manjunatha ,&nbsp;Devarajan Alagarasan ,&nbsp;Shreyasi Das ,&nbsp;R. Ganesan ,&nbsp;R. Naik ,&nbsp;M. Ramudu","doi":"10.1016/j.optmat.2025.117060","DOIUrl":"10.1016/j.optmat.2025.117060","url":null,"abstract":"<div><div>The formation of heterojunctions presents a novel architecture for photodetector applications, offering an expanded active surface area that enhances light absorption and overall performance. Recently, metal-dichalcogenides have attracted significant interest for future optoelectronic devices due to their exceptional electronic and optical properties. However, their application has been limited to narrow detection ranges. To overcome this, broadband photodetection can be achieved through the combination of two distinct materials in a heterostructure. Among these, SnSe₂ has gained significant attention as a promising material for next-generation optoelectronics. In this work, a vertical heterostructure formed by integrating SnSe₂ with hydrothermally grown TiO₂ nanorods. The TiO₂ nanorods, which were uniformly distributed across the surface, were synthesized using a hydrothermal method, while the SnSe₂ layer was deposited via thermal evaporation. This configuration increases the junction area of the heterostructure, enhancing its performance across a broad spectral range (400–800 nm). Upon 325 nm incidence, the SnSe₂/TiO₂ heterostructure demonstrates a remarkable high responsivity of 34.63 mA/W and a detectivity of 10⁷ Jones. This significantly enhanced optoelectronic performance of the SnSe₂/TiO₂ heterostructure offers great potential for the development of efficient broadband photodetectors.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117060"},"PeriodicalIF":3.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"“Temperature-driven modulation of optical and materialistic properties in chemically deposited NbSe2 thin films”","authors":"Shivani R. Bharucha ,&nbsp;Mehul S. Dave ,&nbsp;Sunil H. Chaki ,&nbsp;Tushar A. Limbani","doi":"10.1016/j.optmat.2025.117059","DOIUrl":"10.1016/j.optmat.2025.117059","url":null,"abstract":"<div><div>The impact of deposition temperature on the morphological, structural, and optical characteristics of NbSe₂ thin films deposited via chemical bath deposition at room temperature (R.T.), 70 °C, and 100 °C was comprehensively studied. The NbSe₂ thin films exhibited distinct color variations correlated with deposition temperature; alongside compositional purity confirmed through elemental analysis. X-ray diffraction (XRD) revealed crystalline NbSe₂ with lattice parameters a = b = 3.446 Å and c = 12.55 Å, while SEM and TEM analyses demonstrated reduced agglomeration and enhanced dispersion with increasing temperature. FT-IR spectra confirmed characteristic NbSe₂ chalcogenide groups and additional functional groups, while Raman spectroscopy highlighted shifts in the A1g mode, indicating stronger interlayer bonding and enhanced structural integrity at higher temperatures. Optical analysis showed a decrease in direct bandgap energies from 1.23 eV at R.T. to 1.13 eV at 100 °C, with a concurrent reduction in Urbach energy from 0.13 eV to 0.07 eV, signifying improved structural order.</div><div>The results highlight the substantial influence of deposition temperature on the crystallinity, shape, and electrical characteristics of NbSe₂ thin films. Elevated temperatures augment structural integrity, diminish defect density, and increase optical properties, so establishing a direct correlation between temperature and material performance. The decrease in bandgap and Urbach energy signifies enhanced charge transfer, making these films suitable for photodetectors, transistors, and energy storage applications. Improved dispersion further facilitates their use in nanoscale electrical and sensing applications, which require stability and homogeneity.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117059"},"PeriodicalIF":3.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Near-infrared scintillation properties of Er-doped Ca3TaGa3Si2O14 single crystals grown by floating zone method","authors":"Ryosei Takahashi,&nbsp;Kai Okazaki,&nbsp;Daisuke Nakauchi,&nbsp;Takumi Kato,&nbsp;Noriaki Kawaguchi,&nbsp;Takayuki Yanagida","doi":"10.1016/j.optmat.2025.117064","DOIUrl":"10.1016/j.optmat.2025.117064","url":null,"abstract":"<div><div>Er-doped Ca₃TaGa₃Si₂O₁₄ (Er:CTGS) single crystals doped with different Er concentrations (0.5, 1, 2, and 5 %) were grown by the optical floating zone method. Their luminescence and scintillation performances were investigated. The prepared samples showed emission peaks and decay time constants due to electronic transitions of Er³⁺ under both the visible light and X-ray irradiations. In the photoluminescence quantum yield measurements, the 0.5, 1, 2, and 5 % Er:CTGS samples respectively demonstrated 74.7, 78.0, 83.4, and 63.2 %. Good linear responses between X-ray exposure dose-rate and scintillation output were confirmed, and 2 % Er:CTGS showed the lower detection limit of 2.3 mGy/h.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117064"},"PeriodicalIF":3.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}