Optical Materials最新文献

{"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}

{"title":"Chalcogenide p-type absorber layer studies of spray pyrolyzed CuZnS thin films for heterojunction solar cell applications","authors":"Deepa ,&nbsp;M. Anantha Sunil ,&nbsp;Sabina Rahaman ,&nbsp;K.B. Jagannatha ,&nbsp;Kilari Naveen Kumar","doi":"10.1016/j.optmat.2025.117036","DOIUrl":"10.1016/j.optmat.2025.117036","url":null,"abstract":"<div><div>Automated spray pyrolysis technique is used to deposit Copper Zinc Sulphide (CZS) thin films onto the soda lime glass substrates. The various properties of the CZS films are examined by altering the substrate temperature between 250 °C and 350 °C. XRD analysis reveals the formation of a crystalline mixed CuS–ZnS binary composite with preferred orientation along the (111) and (220) planes, which is confirmed by Raman spectroscopy. Morphological studies showed dense flower shaped structures with the increase in substrate temperature. Optical analysis of the as-deposited CuZnS thin films showed absorption coefficient of around 10⁵ cm⁻¹. The band gap energy of prepared CuZnS thin films is found to be in the range of 1.33 eV–1.55 eV. CuZnS films demonstrated p-type conductivity with a carrier concentration of order 10²¹ cm⁻³ and an electrical conductivity 10³ S/cm. XPS analysis confirmed the formation of oxidation states of copper, zinc and sulphur.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117036"},"PeriodicalIF":3.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851754","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":"Monazite LaPO4: Eu nanorods annealed in air atmosphere: Luminescence optimization and co-existence of Eu2+/Eu3+","authors":"Joana Noelia Mendoza ,&nbsp;María Belén Gilliard ,&nbsp;Irene María Julieta Vilella ,&nbsp;Beatriz Teresita Pierini ,&nbsp;Silvia Alejandra Alconchel","doi":"10.1016/j.optmat.2025.117062","DOIUrl":"10.1016/j.optmat.2025.117062","url":null,"abstract":"<div><div>Monazite LaPO₄: 2–25 mol% Eu nanorods were synthesized using a simple homogeneous co-precipitation method followed by calcination in air at 800 °C. Their luminescence properties were optimized by annealing in the same atmosphere at 1200 °C. The effects caused by this post-synthesis treatment on the structure, morphology and luminescence properties of the nanorods were analysed using X-ray diffraction (XRD), transmission electronic microscopy (TEM), Fourier transform infrared spectroscopy (FTIRS), photoluminescence spectroscopy (PLS) and laser scanning confocal microscopy (LSCM). The quality of the monazite phase was improved at 1200 °C and the rod-shaped (100 nm) particles were converted into pseudo-oval sintered grains of 140 nm. The maximum orange-red light emission of Eu³⁺ excited by 393 nm, with high color purity (93–98 %) and a phosphorescence lifetime of 4 ms was found at 20 mol% Eu. This optimal concentration was verified by X-ray fluorescence (XRF) and X-ray photoelectron spectroscopy (XPS). The co-existence of Eu²⁺/Eu³⁺ in the surface of the grains of LaPO₄: 20 mol% Eu was proved by analysis of the Eu 3d/4d core levels and valence band spectra. The relative fraction of Eu²⁺ was calculated and compared with that of C–Eu₂O₃, taking into account the “surface valence transition” phenomenon. This is the first report that proves the co-existence of Eu²⁺/Eu³⁺ in LaPO₄: Eu monazite treated in an oxidant environment.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117062"},"PeriodicalIF":3.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870757","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":"Passively mode-locking fiber lasers for generating high repetition frequency pulse based on MoWSe2 saturable absorbers","authors":"Fei Wang ,&nbsp;Shixian Sun ,&nbsp;Xiangchen Zhang ,&nbsp;Hao Tan ,&nbsp;Guangzhao Zhu ,&nbsp;Weijie Xu ,&nbsp;Yajun Huang ,&nbsp;Mingzhi Sun ,&nbsp;Yuming Jia ,&nbsp;Zhao Li ,&nbsp;Caixun Bai ,&nbsp;Wenfei Zhang ,&nbsp;Cheng Lu ,&nbsp;Huanian Zhang ,&nbsp;Guomei Wang ,&nbsp;Shenggui Fu","doi":"10.1016/j.optmat.2025.117054","DOIUrl":"10.1016/j.optmat.2025.117054","url":null,"abstract":"<div><div>Transition metal dichalcogenides (TMDs) have increasingly attracted the interest of researchers due to their exceptional physical and chemical properties and broad application prospects. Currently, research on the application potential of the novel ternary TMD alloy MoWSe₂ as a saturable absorber (SA) is not yet mature. This artical achieves mode-locking for the first time after implementing Q-switching in MoWSe₂ SA. This study employed the liquid-phase exfoliation (LPE) method to fabricate a high-quality MoWSe₂ SA with a modulation depth of 7.9 % and a saturation intensity of 14.7 MW/cm². Stable conventional solitons (CS) and harmonic mode-locking (HML) of multiple orders were achieved. The highest order of HML reached the 86th order, with a maximum repetition frequency of 374.8 MHz. This represents the highest repetition frequency achieved to date in fiber lasers based on a MoWSe₂ SA. The results show that MoWSe₂ SA exhibits excellent nonlinear optical modulation performance, which lays the foundation for its role in advancing academic exploration and innovation in engineering practice in the field of ultrafast photonics.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117054"},"PeriodicalIF":3.8,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834807","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":"Optimizing B2O3–Bi2O3–K2O glass via Al2O3 doping: Structural, thermal, optical absorption, elastic moduli, and γ-ray attenuation behavior","authors":"Abely E. Mwakuna ,&nbsp;K. Samatha ,&nbsp;Reddipalli Trisanjya ,&nbsp;R.K.N.R. Manepalli","doi":"10.1016/j.optmat.2025.117053","DOIUrl":"10.1016/j.optmat.2025.117053","url":null,"abstract":"<div><div>Utilizing the thermal fusion and rapid cooling technique, AKB glasses with the chemical formula (65-x)B₂O₃–15Bi₂O₃–20K₂O-xAl₂O₃ (0.0 ≤ x ≤ 1.2 mol%) were synthesized to systematically examine the role of Al₂O₃ in enhancing the structural, thermal, optical absorption, elastic moduli, and γ-ray attenuation behavior. The non-crystalline structure of the glasses was affirmed via XRD analysis. FTIR spectroscopy revealed that the incorporation of Al₂O₃ up to 0.6 mol% promotes the transformation of BO₃ units into BO₄ units, facilitating the development of additional non-bridging oxygen sites. However, beyond 0.6 mol% Al₂O₃, the formation of [AlO₄]^- units becomes more dominant compared to the highly distorted [AlO₆]^3- units. These [AlO₄]^- units interact with non-bridging oxygen atoms, facilitating charge stabilization and enhancing cross-linking within the glass network. A rise in density accompanied by a decline in molar volume, suggests a compaction of the glass network with increasing Al₂O₃ concentration. The optical band gap exhibited a decreasing trend up to 0.6 mol% Al₂O₃, indicating an increase in structural disorder. Nevertheless, for Al₂O₃ concentrations exceeding 0.6 mol%, the optical band gap increased, suggesting a transition toward a more ordered and cross-linked glass structure. DSC analysis further confirmed enhanced thermal stability, with the highest glass transition temperature of 337.556 °C occurring at 0.3 mol% Al₂O₃. The Makishima-Mackenzie model demonstrated an improvement in mechanical properties with Al₂O₃ doping, primarily due to the increase in mean bonding energy density. This enhancement strengthens the glass network, resulting in greater rigidity, superior mechanical stability, and improved overall structural integrity. γ-ray attenuation analysis revealed that the AKB glass samples exhibit superior attenuation efficiency compared to widely used commercial shielding materials, including RS-253-G1 and RS-360. While AKB glasses possess a half-value layer greater than 1.389 cm, exceeding that of RS-520, they still demonstrate superior shielding capabilities relative to concrete and other commercial glass alternatives. Among the AKB glass samples, the AKB0.3 (0.3 mol% Al₂O₃) composition exhibited outstanding thermal stability, as indicated by its higher glass transition temperature. This property makes it highly suitable for radiation shielding at 0.662 MeV, where thermal stability is essential for ensuring optimal performance.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117053"},"PeriodicalIF":3.8,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834811","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":"Photocatalytic properties of C, N-doped TiO2 films prepared via ion-assisted RF magnetron sputtering","authors":"Jeng-Yu Lee ,&nbsp;Jin-Cherng Hsu ,&nbsp;Kuang-Chang Pien ,&nbsp;Yung-Shin Sun ,&nbsp;Hsing-Yu Wu","doi":"10.1016/j.optmat.2025.117061","DOIUrl":"10.1016/j.optmat.2025.117061","url":null,"abstract":"<div><div>Titanium dioxide (TiO₂) is considered one of the most valuable photocatalytic materials due to its unique properties and versatility in various applications. C- or <em>N</em>-doped TiO₂ has been shown to exhibit narrowed band gaps, but codoping of C and N into TiO₂ has seldom been studied. In this study, C, <em>N</em>-doped TiO₂ films were prepared using ion-assisted RF magnetron sputtering. The anatase phase of these films was attained under a substrate temperature of 500 °C in the plasma containing a mixture of CO₂ and N₂. The prepared samples were characterized using X-ray diffraction (XRD), atomic force microscopy (AFM), UV–Vis spectrophotometer, X-ray photoelectron spectroscopy (XPS), and methylene blue degradation experiments. XRD analysis indicated that the crystallinity of the TiO₂ film was weakened when <em>N</em>-doped, while the anatase phase transitioned to rutile after C-doped. XPS analysis revealed the presence of the atomic β-N state in the film, which contributed to the narrowing of its band gap. In the methylene blue degradation experiments, the C, <em>N</em>-doped TiO₂ film prepared with ion-assisted deposition showed the best visible light (460 nm) photocatalytic activity, in accordance with the reduction in its optical band gap. This study demonstrated that the proposed process is effective in reducing the band gap and enhancing the photocatalytic activity of TiO₂ films.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"164 ","pages":"Article 117061"},"PeriodicalIF":3.8,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838988","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}