Pub Date : 2026-06-01Epub Date: 2026-02-12DOI: 10.1016/j.optmat.2026.117960
Muhammad Salik Qureshi , Nadia Shahzad , Ayesha Tabriz , Muhammad Ali Tariq , Muhammad Usman Nawaz , Salman Riaz , Hafiz T. Ali , Muhammad Imran Shahzad
With advancements in the field of perovskite solar cells (PSCs), the research focus has shifted toward long-term stability and resistance to environmental factors. The MAPbI3-based perovskite absorber layer (MAI) often faces issues such as phase instability, moisture degradation, poor morphology, and defect-induced recombination losses. To address these challenges, this study explores the advantages of substituting cesium bromide (CsBr) into MAI. CsBr substitution results in a substantial enhancement of the absorber layer by improving film crystallinity and grain size, along with a reduction in grain boundaries, leading to decreased charge recombination. Consequently, light absorption is enhanced, accompanied by a slight increase in the bandgap. Photoluminescence (PL) studies reveal that the most effective charge transport occurs at the interface between the electron transport layer (ETL) and the CsBr-doped MAPbI3 absorber layer (Cs-MAI). Finally, the champion cell fabricated with Cs-MAI exhibited a photovoltaic conversion efficiency (PCE) of 14.21%, representing a 26.95% improvement compared to its standard counterpart, which showed a PCE of only 10.38%. In addition to improved efficiency, stability testing indicates that the CsBr-based cell demonstrates superior stability, with only a 3.26% drop in PCE over a 30-day period, compared to an 11.80% PCE loss observed in MAI-based cells.
{"title":"Fabrication of HTL free perovskite solar cell using compositional engineering via cesium bromide for ambient fabrication","authors":"Muhammad Salik Qureshi , Nadia Shahzad , Ayesha Tabriz , Muhammad Ali Tariq , Muhammad Usman Nawaz , Salman Riaz , Hafiz T. Ali , Muhammad Imran Shahzad","doi":"10.1016/j.optmat.2026.117960","DOIUrl":"10.1016/j.optmat.2026.117960","url":null,"abstract":"<div><div>With advancements in the field of perovskite solar cells (PSCs), the research focus has shifted toward long-term stability and resistance to environmental factors. The MAPbI<sub>3</sub>-based perovskite absorber layer (MAI) often faces issues such as phase instability, moisture degradation, poor morphology, and defect-induced recombination losses. To address these challenges, this study explores the advantages of substituting cesium bromide (CsBr) into MAI. CsBr substitution results in a substantial enhancement of the absorber layer by improving film crystallinity and grain size, along with a reduction in grain boundaries, leading to decreased charge recombination. Consequently, light absorption is enhanced, accompanied by a slight increase in the bandgap. Photoluminescence (PL) studies reveal that the most effective charge transport occurs at the interface between the electron transport layer (ETL) and the CsBr-doped MAPbI<sub>3</sub> absorber layer (Cs-MAI). Finally, the champion cell fabricated with Cs-MAI exhibited a photovoltaic conversion efficiency (PCE) of 14.21%, representing a 26.95% improvement compared to its standard counterpart, which showed a PCE of only 10.38%. In addition to improved efficiency, stability testing indicates that the CsBr-based cell demonstrates superior stability, with only a 3.26% drop in PCE over a 30-day period, compared to an 11.80% PCE loss observed in MAI-based cells.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117960"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384679","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}
Pub Date : 2026-06-01Epub Date: 2026-02-05DOI: 10.1016/j.optmat.2026.117944
Pedro César Quero–Jiménez , Aracely Hernández–Ramírez , Jorge Luis Guzmán–Mar , Giselle Gomes , Reinaldo Molina–Ruíz , Daniele Maia Bila , Laura Hinojosa–Reyes
The coupling of MOF235(Fe)–derived α–Fe2O3 into ZnO material (MIO@ZO) through a two–step self–assembly process using a microwave–assisted method, followed by calcination at 450 °C, was evaluated in the photocatalytic degradation of a mixture of emerging contaminants (bisphenol A, 4–tert–butylphenol, and 4–tert–octylphenol). This study assessed the efficacy of the photocatalyst (MIO@ZO) in the mineralization of a mixture of these emerging contaminants at neutral pH as well as its stability, functionality, and performance. The photocatalyst demonstrated superior performance, achieving a mineralization rate of 36.76%, compared to 32.08% with pure ZnO.The enhancement is primarily due to the heterostructured catalyst (MIO@ZO), which exhibited a slight increase in surface area, enhanced visible–light absorption, and reduced photoluminescence intensity, indicating a lower electron–hole recombination rate than in ZnO attributable to the heterojunction interface between the α–Fe2O3 and ZnO components. Gas chromatography–mass spectrometry identified several intermediate degradation b–yproducts, such as acetic acid, oxalic acid, 2–hydroxyacetic acid, and ethane–1,2–diol, alongside toxic compounds like 1,3–di–tert–butylbenzene and 2,4–di–tert–butylphenol, as predicted by the ECOSAR program. In vitro toxicity assessments showed a reduction in Vibrio fischeri bioluminescence inhibition from 59% to 31%, indicating a moderate level of toxicity post–treatment. Conversely, in vivo tests with Ceriodaphnia dubia indicated acute toxicity. The YES assay confirmed the absence of estrogenic b–yproducts at the end of the process. The integration of in silico, in vivo, and in vitro approaches provides a comprehensive evaluation of the safety profile of effluents generated by photocatalytic degradation of endocrine–disrupting compounds. The integration of photocatalysis and toxicity testing underscores the importance of ensuring that a significant reduction in environmental risks accompanies contaminant breakdown.
{"title":"Estrogenic and toxicological profile of effluent from degrading a mixture of bisphenol A, 4−tert−butylphenol, and 4−tert−octylphenol using a MOF235(Fe)−derived α−Fe2O3/ZnO photocatalyst","authors":"Pedro César Quero–Jiménez , Aracely Hernández–Ramírez , Jorge Luis Guzmán–Mar , Giselle Gomes , Reinaldo Molina–Ruíz , Daniele Maia Bila , Laura Hinojosa–Reyes","doi":"10.1016/j.optmat.2026.117944","DOIUrl":"10.1016/j.optmat.2026.117944","url":null,"abstract":"<div><div>The coupling of MOF235(Fe)–derived α–Fe<sub>2</sub>O<sub>3</sub> into ZnO material (MIO@ZO) through a two–step self–assembly process using a microwave–assisted method, followed by calcination at 450 °C, was evaluated in the photocatalytic degradation of a mixture of emerging contaminants (bisphenol A, 4–<em>tert</em>–butylphenol, and 4–<em>tert</em>–octylphenol). This study assessed the efficacy of the photocatalyst (MIO@ZO) in the mineralization of a mixture of these emerging contaminants at neutral pH as well as its stability, functionality, and performance. The photocatalyst demonstrated superior performance, achieving a mineralization rate of 36.76%, compared to 32.08% with pure ZnO.The enhancement is primarily due to the heterostructured catalyst (MIO@ZO), which exhibited a slight increase in surface area, enhanced visible–light absorption, and reduced photoluminescence intensity, indicating a lower electron–hole recombination rate than in ZnO attributable to the heterojunction interface between the α–Fe<sub>2</sub>O<sub>3</sub> and ZnO components. Gas chromatography–mass spectrometry identified several intermediate degradation b–yproducts, such as acetic acid, oxalic acid, 2–hydroxyacetic acid, and ethane–1,2–diol, alongside toxic compounds like 1,3–di–<em>tert</em>–butylbenzene and 2,4–di–<em>tert</em>–butylphenol, as predicted by the ECOSAR program. <em>In vitro</em> toxicity assessments showed a reduction in <em>Vibrio fischeri</em> bioluminescence inhibition from 59% to 31%, indicating a moderate level of toxicity post–treatment. Conversely, <em>in vivo</em> tests with <em>Ceriodaphnia dubia</em> indicated acute toxicity. The YES assay confirmed the absence of estrogenic b–yproducts at the end of the process. The integration of <em>in silico</em>, <em>in vivo</em>, and <em>in vitro</em> approaches provides a comprehensive evaluation of the safety profile of effluents generated by photocatalytic degradation of endocrine–disrupting compounds. The integration of photocatalysis and toxicity testing underscores the importance of ensuring that a significant reduction in environmental risks accompanies contaminant breakdown.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117944"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384680","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}
Pub Date : 2026-06-01Epub Date: 2026-02-06DOI: 10.1016/j.optmat.2026.117939
Silvia Ruggieri , Albano N. Carneiro Neto , Carlos V. Santos Jr. , Renaldo T. MouraJr , Marco Bettinelli , Fabio Piccinelli
In this contribution, the f-f spectroscopy of two racemic nitrate Eu(III) complexes containing an imine-based (i.e. [N,N′-bis(2-pyridylmethylidene)-1,2-(R,R)+(S,S)-cyclohexanediamine]) (complex 1) and an amine-based (i.e. [N,N′-bis(2-pyridylmethylene)-1,2-(R,R + S,S)-cyclohexanediamine]) (complexes 2) ligands has been revisited, in the light of the recent redefinition of the “asymmetry ratio” R2 [ as “hypersensitive ratio”, with regard to the luminescence in the visible spectral range of Eu(III) ion, stemming from the 5D0 level. We demonstrate, by means of computational calculations, that R2 directly connected to the Ω2 intensity parameter, in turn dominated by a dynamic ligand polarization mechanism (dynamic coupling, DC), is significantly affected by the polarizability of the oxygen and nitrogen ligating atoms, more than by the geometric environment around Eu(III). The larger R2 value of complex 1 is ascribable to the lower polarizability of the sp2 hybridized nitrogens of the iminic ligand involved in the resonance phenomenon together with the hetero-aromatic pyridine rings.
{"title":"Effect of the ligand polarizability on the hypersensitive 5D0→7F2 transition of Eu(III) in nitrate complexes with nitrogen-based ligands","authors":"Silvia Ruggieri , Albano N. Carneiro Neto , Carlos V. Santos Jr. , Renaldo T. MouraJr , Marco Bettinelli , Fabio Piccinelli","doi":"10.1016/j.optmat.2026.117939","DOIUrl":"10.1016/j.optmat.2026.117939","url":null,"abstract":"<div><div>In this contribution, the <em>f-f</em> spectroscopy of two racemic nitrate Eu(III) complexes containing an imine-based (<em>i.e.</em> [N,N′-bis(2-pyridylmethylidene)-1,2-(R,R)+(S,S)-cyclohexanediamine]) (<strong>complex 1</strong>) and an amine-based (<em>i.e.</em> [N,N′-bis(2-pyridylmethylene)-1,2-(R,R + S,S)-cyclohexanediamine]) (<strong>complexes 2</strong>) ligands has been revisited, in the light of the recent redefinition of the “asymmetry ratio” <em>R2</em> [<span><math><mrow><mrow><mrow><mi>I</mi><mrow><mo>(</mo><mrow><mmultiscripts><msub><mi>D</mi><mn>0</mn></msub><mprescripts></mprescripts><none></none><mn>5</mn></mmultiscripts><mo>→</mo><mmultiscripts><msub><mi>F</mi><mn>2</mn></msub><mprescripts></mprescripts><none></none><mn>7</mn></mmultiscripts></mrow><mo>)</mo></mrow></mrow><mo>/</mo><mrow><mi>I</mi><mrow><mo>(</mo><mrow><mmultiscripts><msub><mi>D</mi><mn>0</mn></msub><mprescripts></mprescripts><none></none><mn>5</mn></mmultiscripts><mo>→</mo><mmultiscripts><msub><mi>F</mi><mn>1</mn></msub><mprescripts></mprescripts><none></none><mn>7</mn></mmultiscripts></mrow><mo>)</mo></mrow></mrow></mrow><mo>]</mo></mrow></math></span> as “hypersensitive ratio”, with regard to the luminescence in the visible spectral range of Eu(III) ion, stemming from the <sup>5</sup>D<sub>0</sub> level. We demonstrate, by means of computational calculations, that <em>R2</em> directly connected to the Ω<sub>2</sub> intensity parameter, in turn dominated by a dynamic ligand polarization mechanism (dynamic coupling, DC), is significantly affected by the polarizability of the oxygen and nitrogen ligating atoms, more than by the geometric environment around Eu(III). The larger <em>R2</em> value of <strong>complex 1</strong> is ascribable to the lower polarizability of the <em>sp</em><sup><em>2</em></sup> hybridized nitrogens of the iminic ligand involved in the resonance phenomenon together with the hetero-aromatic pyridine rings.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117939"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384681","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}
Pub Date : 2026-06-01Epub Date: 2026-02-13DOI: 10.1016/j.optmat.2026.117965
A. Runts , G. Bleykher , D. Baboshko , A. Pirozhkov , S. Stepanov , D. Valiev
This work is devoted to the formation of YAG:Ce3+ phosphor coatings using mid-frequency magnetron sputtering of a set of metallic yttrium, aluminum, and cerium targets in an argon-oxygen gas mixture. This method allows for an increase in the deposition rate of the (Y–Al–O):Ce precursor coating by more than an order of magnitude compared to RF reactive magnetron sputtering of ceramic targets. The surface morphology, microstructure, phase and elemental composition, as well as the optical and cathodoluminescent (CL) properties of the synthesized YAG:Ce coatings were studied at different annealing temperatures during high-temperature annealing in air (800–1200 °C) and at different heating/cooling rates (2 and 7 °C/min). The CL spectra demonstrate the presence of radiative transitions in Ce3+ ions. It was found that the CL intensity is significantly higher in samples annealed at a heating rate of 2 °C/min, which correlates with a lower concentration of microdefects and greater phase composition homogeneity of the synthesized coatings. The intensity increases with annealing temperature in the range from 490 to 850 nm. The proposed approach can potentially be used to create luminescent coatings with high emission properties.
{"title":"Effect of high-temperature annealing parameters on the structure and properties of YAG:Ce phosphor coatings deposited via mid-frequency magnetron sputtering","authors":"A. Runts , G. Bleykher , D. Baboshko , A. Pirozhkov , S. Stepanov , D. Valiev","doi":"10.1016/j.optmat.2026.117965","DOIUrl":"10.1016/j.optmat.2026.117965","url":null,"abstract":"<div><div>This work is devoted to the formation of YAG:Ce<sup>3+</sup> phosphor coatings using mid-frequency magnetron sputtering of a set of metallic yttrium, aluminum, and cerium targets in an argon-oxygen gas mixture. This method allows for an increase in the deposition rate of the (Y–Al–O):Ce precursor coating by more than an order of magnitude compared to RF reactive magnetron sputtering of ceramic targets. The surface morphology, microstructure, phase and elemental composition, as well as the optical and cathodoluminescent (CL) properties of the synthesized YAG:Ce coatings were studied at different annealing temperatures during high-temperature annealing in air (800–1200 °C) and at different heating/cooling rates (2 and 7 °C/min). The CL spectra demonstrate the presence of radiative transitions in Ce<sup>3+</sup> ions. It was found that the CL intensity is significantly higher in samples annealed at a heating rate of 2 °C/min, which correlates with a lower concentration of microdefects and greater phase composition homogeneity of the synthesized coatings. The intensity increases with annealing temperature in the range from 490 to 850 nm. The proposed approach can potentially be used to create luminescent coatings with high emission properties.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117965"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384685","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}
Pub Date : 2026-06-01Epub Date: 2026-02-06DOI: 10.1016/j.optmat.2026.117935
Yingying Zhao, Qiurui Ma, Shifeng Zhu, Xuexin Liang, Songyu Wang
A novel Schiff base sensor 3-(4-(diethylamino)-2-hydroxybenzylidene) amino benzo[b]thiophene-2-carbohydrazide (Z) was synthesized and discovered to be useful for the sequential detection of Cu2+ and S2−. Z exhibited high sensitivity (LOD = 1.20 × 10−8 M) and selectivity towards Cu2+ through a 1:2 binding mode with a large stokes shift (148 nm). Furthermore, the complex Z-Cu2+ can be used as a sensor to further detect S2−. This “on-off-on” process can easily occur in 1 min. Job's plot analysis and DFT (density functional theory) calculations all validated the sensing process. In addition, the fluorescence intensity of Z which was quenched by Cu2+ could be restored in the presence of an equal amount of EDTA, and thus sensor Z could simulate the INHIBIT logic function by employing Cu2+ and EDTA as logic inputs and fluorescence intensity at 526 nm as an output signal. Moreover, Z may be utilized to determine target ions in real water samples and plant samples. This study also proposed the possible application of Z in the transmission of invisible ink for confidential information.
{"title":"A fluorescence sensor with large stokes shift based on 3-aminobenzo[b]thiophene derivatives for the sequential detection of Cu2+ and S2− and its applications","authors":"Yingying Zhao, Qiurui Ma, Shifeng Zhu, Xuexin Liang, Songyu Wang","doi":"10.1016/j.optmat.2026.117935","DOIUrl":"10.1016/j.optmat.2026.117935","url":null,"abstract":"<div><div>A novel Schiff base sensor 3-(4-(diethylamino)-2-hydroxybenzylidene) amino benzo[b]thiophene-2-carbohydrazide (<strong>Z</strong>) was synthesized and discovered to be useful for the sequential detection of Cu<sup>2+</sup> and S<sup>2−</sup>. <strong>Z</strong> exhibited high sensitivity (LOD = 1.20 × 10<sup>−8</sup> M) and selectivity towards Cu<sup>2+</sup> through a 1:2 binding mode with a large stokes shift (148 nm). Furthermore, the complex <strong>Z</strong>-Cu<sup>2+</sup> can be used as a sensor to further detect S<sup>2−</sup>. This “on-off-on” process can easily occur in 1 min. Job's plot analysis and DFT (density functional theory) calculations all validated the sensing process. In addition, the fluorescence intensity of <strong>Z</strong> which was quenched by Cu<sup>2+</sup> could be restored in the presence of an equal amount of EDTA, and thus sensor <strong>Z</strong> could simulate the INHIBIT logic function by employing Cu<sup>2+</sup> and EDTA as logic inputs and fluorescence intensity at 526 nm as an output signal. Moreover, <strong>Z</strong> may be utilized to determine target ions in real water samples and plant samples. This study also proposed the possible application of <strong>Z</strong> in the transmission of invisible ink for confidential information.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117935"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384779","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}
Pub Date : 2026-06-01Epub Date: 2026-01-20DOI: 10.1016/j.optmat.2026.117903
Y. Vygranenko , G. Lavareda , A. Amaral , P. Brogueira
Hydrogenated amorphous silicon carbonitride (a-SiCN:H) thin films were deposited by radio-frequency plasma-enhanced chemical vapor deposition (rf-PECVD) at 150 °C using SiH4, CH4, and NH3 gas mixtures with variable flow ratios. The chemical composition and hydrogen content, determined by Rutherford backscattering and elastic recoil detection analyses, revealed Si-rich carbonitrides containing 32–52 at.% Si, 3–5 at.% C, 16–44 at.% N, and 25–30 at.% H. Atomic force microscopy confirmed smooth and uniform film surfaces with RMS roughness below 1 nm, suitable for precise optical modeling. Optical transmission spectra were analyzed using an extended Tauc–Lorentz (XTL) dispersion model capable of describing non-exponential band-tail absorption. The XTL model provided excellent agreement with experiment and allowed extraction of the real and imaginary parts of the dielectric function, including sub-gap components. The optical bandgap, derived from Tauc plots, increased linearly with the elemental N/Si ratio, reflecting enhanced Si–N bond formation and a reduction in localized electronic states. The refractive index varied between 1.77 and 2.9, showing strong dependence on composition and photon energy. These results demonstrate that rf-PECVD enables low-temperature synthesis of uniform a-SiCN:H films with controllable optical properties, suitable for optoelectronic and photonic device applications.
{"title":"Composition-dependent optical properties and dielectric function modeling of PECVD-grown hydrogenated amorphous silicon carbonitride thin films","authors":"Y. Vygranenko , G. Lavareda , A. Amaral , P. Brogueira","doi":"10.1016/j.optmat.2026.117903","DOIUrl":"10.1016/j.optmat.2026.117903","url":null,"abstract":"<div><div>Hydrogenated amorphous silicon carbonitride (a-SiCN:H) thin films were deposited by radio-frequency plasma-enhanced chemical vapor deposition (rf-PECVD) at 150 °C using SiH<sub>4</sub>, CH<sub>4</sub>, and NH<sub>3</sub> gas mixtures with variable flow ratios. The chemical composition and hydrogen content, determined by Rutherford backscattering and elastic recoil detection analyses, revealed Si-rich carbonitrides containing 32–52 at.% Si, 3–5 at.% C, 16–44 at.% N, and 25–30 at.% H. Atomic force microscopy confirmed smooth and uniform film surfaces with RMS roughness below 1 nm, suitable for precise optical modeling. Optical transmission spectra were analyzed using an extended Tauc–Lorentz (XTL) dispersion model capable of describing non-exponential band-tail absorption. The XTL model provided excellent agreement with experiment and allowed extraction of the real and imaginary parts of the dielectric function, including sub-gap components. The optical bandgap, derived from Tauc plots, increased linearly with the elemental N/Si ratio, reflecting enhanced Si–N bond formation and a reduction in localized electronic states. The refractive index varied between 1.77 and 2.9, showing strong dependence on composition and photon energy. These results demonstrate that rf-PECVD enables low-temperature synthesis of uniform a-SiCN:H films with controllable optical properties, suitable for optoelectronic and photonic device applications.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117903"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025523","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}
Pub Date : 2026-06-01Epub Date: 2026-01-19DOI: 10.1016/j.optmat.2026.117900
Hussein A. Elsayed , Mohamed Bouzidi , Ahmad Al-Qawasmeh , Abdelhamid Albaid , Ahmed Mehaney , Ahmed A. Aboud
This study systematically investigates the effect of film thickness on the physical properties of Pb-doped ZnO thin films, prepared via Aerosol-Assisted Chemical Vapor Deposition (AACVD) with a constant 5 wt% Pb concentration. In this regard, X-ray diffraction confirms a hexagonal ZnO phase with a dominant (100) orientation, while the intensities of (002) and (101) planes increase with thickness, indicating an evolution in preferred orientation. Additionally, our quantitative analysis reveals that the significant variation in crystallite size estimates from different methods points to the presence of anisotropic strain. Critically, out-of-plane compressive strain, pronounced in thinner films, relaxes substantially with increasing thickness. X-ray photoelectron spectroscopy (XPS) confirms the presence of Pb in the 4+ oxidation state, suggesting that charge compensation mechanisms, rather than direct ionic substitution, moderate its incorporation into the lattice. This strain relaxation governs the structural evolution, as evidenced by FESEM, which shows a morphological transition to elongated grains. Optically, the thinnest films exhibit an excitonic shoulder, which vanishes in thicker films, allowing for the determination of a single direct band gap (3.30–3.45 eV). Finally, DC conductivity decreases with thickness due to the increased grain-boundary scattering, with the activation energies around 1 eV. This work decouples the role of thickness from doping, demonstrating that both strain relaxation and microstructural evolution are the primary drivers of property changes in Pb:ZnO thin films.
{"title":"Thickness dependent physical properties of Pb-doped ZnO thin films prepared using AACVD","authors":"Hussein A. Elsayed , Mohamed Bouzidi , Ahmad Al-Qawasmeh , Abdelhamid Albaid , Ahmed Mehaney , Ahmed A. Aboud","doi":"10.1016/j.optmat.2026.117900","DOIUrl":"10.1016/j.optmat.2026.117900","url":null,"abstract":"<div><div>This study systematically investigates the effect of film thickness on the physical properties of Pb-doped ZnO thin films, prepared via Aerosol-Assisted Chemical Vapor Deposition (AACVD) with a constant 5 wt% Pb concentration. In this regard, X-ray diffraction confirms a hexagonal ZnO phase with a dominant (100) orientation, while the intensities of (002) and (101) planes increase with thickness, indicating an evolution in preferred orientation. Additionally, our quantitative analysis reveals that the significant variation in crystallite size estimates from different methods points to the presence of anisotropic strain. Critically, out-of-plane compressive strain, pronounced in thinner films, relaxes substantially with increasing thickness. X-ray photoelectron spectroscopy (XPS) confirms the presence of Pb in the 4+ oxidation state<strong>,</strong> suggesting that charge compensation mechanisms, rather than direct ionic substitution, moderate its incorporation into the lattice. This strain relaxation governs the structural evolution, as evidenced by FESEM, which shows a morphological transition to elongated grains. Optically, the thinnest films exhibit an excitonic shoulder, which vanishes in thicker films, allowing for the determination of a single direct band gap (3.30–3.45 eV). Finally, DC conductivity decreases with thickness due to the increased grain-boundary scattering, with the activation energies around 1 eV. This work decouples the role of thickness from doping, demonstrating that both strain relaxation and microstructural evolution are the primary drivers of property changes in Pb:ZnO thin films.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117900"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025524","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}
Pub Date : 2026-06-01Epub Date: 2026-02-11DOI: 10.1016/j.optmat.2026.117953
Qiao Liang , Haoxuan Zeng , Ziyuan Li , Taihui Chen , Lu He , Shuquan Xi , Xiaoli Wu
Fluoroxide, combining the low phonon energy of fluoride materials with the excellent thermal and chemical stability of oxides, are recognized as outstanding luminescent matrix materials. However, the traditional synthesis methods (sol-gel, spray drying, and combustion synthesis) suffer from organic residues, high equipment dependency, and product defects. To address the limitations, we developed a two-step strategy. This method involves first preparing Na2LaF5 precursors via a hydrothermal reaction at 150oC for 2 h using layered lanthanum hydroxide and excess NaF, followed by precise heat treatment (300-1000 °C) to controllably synthesize cubic, tetragonal, and hexagonal LaOF crystals. Leveraging the high sensitivity of the human eye to the red/green spectral regions and the micrometer-sized particle characteristics of the synthesized LaOF, hexagonal LaOF: RE3+ (RE3+ = Eu3+, Tb3+) phosphors were developed for fingerprint recognition applications. These phosphors can visualize potential fingerprints with high contrast on various substrates, including contaminated surfaces, demonstrating excellent imaging clarity and resistance to background interference. The material can clearly identify more than ten typical detail features, such as creases, forks and sweat pores.
{"title":"Controllable synthesis of LaOF:RE3+ phosphors and their application in fingerprint recognition","authors":"Qiao Liang , Haoxuan Zeng , Ziyuan Li , Taihui Chen , Lu He , Shuquan Xi , Xiaoli Wu","doi":"10.1016/j.optmat.2026.117953","DOIUrl":"10.1016/j.optmat.2026.117953","url":null,"abstract":"<div><div>Fluoroxide, combining the low phonon energy of fluoride materials with the excellent thermal and chemical stability of oxides, are recognized as outstanding luminescent matrix materials. However, the traditional synthesis methods (sol-gel, spray drying, and combustion synthesis) suffer from organic residues, high equipment dependency, and product defects. To address the limitations, we developed a two-step strategy. This method involves first preparing Na<sub>2</sub>LaF<sub>5</sub> precursors via a hydrothermal reaction at 150<sup>o</sup>C for 2 h using layered lanthanum hydroxide and excess NaF, followed by precise heat treatment (300-1000 °C) to controllably synthesize cubic, tetragonal, and hexagonal LaOF crystals. Leveraging the high sensitivity of the human eye to the red/green spectral regions and the micrometer-sized particle characteristics of the synthesized LaOF, hexagonal LaOF: RE<sup>3+</sup> (RE<sup>3+</sup> = Eu<sup>3+</sup>, Tb<sup>3+</sup>) phosphors were developed for fingerprint recognition applications. These phosphors can visualize potential fingerprints with high contrast on various substrates, including contaminated surfaces, demonstrating excellent imaging clarity and resistance to background interference. The material can clearly identify more than ten typical detail features, such as creases, forks and sweat pores.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117953"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384682","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}
Pub Date : 2026-06-01Epub Date: 2026-02-10DOI: 10.1016/j.optmat.2026.117952
Yuzhen Li , Tianyu Qi , Kevin Zhang , Zhengping Wang , Fapeng Yu , Shiyi Guo
Single crystal of Ca3Nb(Ga0.5Al0.5)3Si2O14 were grown via the Czochralski method. The crystal's growth conditions, structure, and composition were characterized. Its thermal properties, including specific heat, thermal stability, thermal expansion, thermal diffusivity, and thermal conductivity, were systematically investigated. Optical transmission measurements revealed ultraviolet and infrared cut-off edges at 267 nm and 5073 nm, respectively. The refractive indices were determined experimentally, and Sellmeier's equation along with its parameters were derived by fitting the data. Based on these results, the refractive index dispersion curves were fitted, and the phase-matching angles, acceptance angles, and walk-off angles for both type I and type II configurations were calculated. Frequency-doubling crystals were fabricated with dimensions of 4 × 4 × 8.44 mm3 (type I), 4 × 4 × 8.44 mm3 (type II), and 4 × 4 × 12.47 mm3 (type II). Experimentally optimization phase-matching angles were θm(I) = 39.85° and θm(II) = 62.88° for fundamental light 1064 nm. With a fundamental 1064 nm pump energy of 1.35 mJ, the generated 532 nm output energies were 37.5 μJ, 41.25 μJ, and 50 μJ, corresponding to conversion efficiencies of 2.7%, 3.1%, and 3.7%, respectively. This study demonstrates that the equimolar Al/Ga composition offers a balanced combination of wide transparency, favorable thermal stability, and viable nonlinear optical performance, suggesting its potential as a candidate material for frequency-doubling applications.
{"title":"Effects of equimolar Al/Ga substitution on crystal growth, thermal stability, and nonlinear optical properties of Ca3Nb(Ga0.5Al0.5)3Si2O14","authors":"Yuzhen Li , Tianyu Qi , Kevin Zhang , Zhengping Wang , Fapeng Yu , Shiyi Guo","doi":"10.1016/j.optmat.2026.117952","DOIUrl":"10.1016/j.optmat.2026.117952","url":null,"abstract":"<div><div>Single crystal of Ca<sub>3</sub>Nb(Ga<sub>0.5</sub>Al<sub>0.5</sub>)<sub>3</sub>Si<sub>2</sub>O<sub>14</sub> were grown via the Czochralski method. The crystal's growth conditions, structure, and composition were characterized. Its thermal properties, including specific heat, thermal stability, thermal expansion, thermal diffusivity, and thermal conductivity, were systematically investigated. Optical transmission measurements revealed ultraviolet and infrared cut-off edges at 267 nm and 5073 nm, respectively. The refractive indices were determined experimentally, and Sellmeier's equation along with its parameters were derived by fitting the data. Based on these results, the refractive index dispersion curves were fitted, and the phase-matching angles, acceptance angles, and walk-off angles for both type I and type II configurations were calculated. Frequency-doubling crystals were fabricated with dimensions of 4 × 4 × 8.44 mm<sup>3</sup> (type I), 4 × 4 × 8.44 mm<sup>3</sup> (type II), and 4 × 4 × 12.47 mm<sup>3</sup> (type II). Experimentally optimization phase-matching angles were θ<sub>m</sub>(I) = 39.85° and θ<sub>m</sub>(II) = 62.88° for fundamental light 1064 nm. With a fundamental 1064 nm pump energy of 1.35 mJ, the generated 532 nm output energies were 37.5 μJ, 41.25 μJ, and 50 μJ, corresponding to conversion efficiencies of 2.7%, 3.1%, and 3.7%, respectively. This study demonstrates that the equimolar Al/Ga composition offers a balanced combination of wide transparency, favorable thermal stability, and viable nonlinear optical performance, suggesting its potential as a candidate material for frequency-doubling applications.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117952"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147384780","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}
Pub Date : 2026-06-01Epub Date: 2026-02-12DOI: 10.1016/j.optmat.2026.117962
Shiqi Lou , Yiming Bao , Guiying Wang
Long-lasting SrAl2O4: Eu2+, Dy3+ phosphors are widely employed due to their high luminous intensity and long afterglow time. However, these materials are susceptible to hydrolysis in humid environments. To address this problem, the surface of phosphor was coated with the SiO2 layers by heterogeneous precipitation method, and then modified with silane coupling agent KH570. The effects of different treatments were systematically compared, including SiO2 coated alone, continuous coated and stepwise coated. X-ray diffraction (XRD) demonstrated that the physical phase and crystal structure were intact. The Si–O and CO peaks in Fourier transform infrared spectroscopy (FT-IR) confirmed successful modification. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) revealed that the phosphor surface was smooth after coating, with a uniform and dense inorganic/organic composite layer. Fluorescence spectroscopy and pH analysis demonstrated that all three coated samples exhibited a significant improvement in water resistance, with only a slight reduction in luminescence intensity. Among these, the residual luminescence intensity of the continuously coated samples was 84.2% after 24h of water immersion, significantly higher than the uncoated samples. Finally, the application value of water-based coatings was preliminarily explored in the field of anti-counterfeit coatings by using continuously coated phosphors as fillers.
{"title":"Enhancement of water resistance of SrAl2O4:Eu2+, Dy3+ phosphors via SiO2/KH570 composite coating and application in transparent anti-counterfeiting coatings","authors":"Shiqi Lou , Yiming Bao , Guiying Wang","doi":"10.1016/j.optmat.2026.117962","DOIUrl":"10.1016/j.optmat.2026.117962","url":null,"abstract":"<div><div>Long-lasting SrAl<sub>2</sub>O<sub>4</sub>: Eu<sup>2+</sup>, Dy<sup>3+</sup> phosphors are widely employed due to their high luminous intensity and long afterglow time. However, these materials are susceptible to hydrolysis in humid environments. To address this problem, the surface of phosphor was coated with the SiO<sub>2</sub> layers by heterogeneous precipitation method, and then modified with silane coupling agent KH570. The effects of different treatments were systematically compared, including SiO<sub>2</sub> coated alone, continuous coated and stepwise coated. X-ray diffraction (XRD) demonstrated that the physical phase and crystal structure were intact. The Si–O and C<img>O peaks in Fourier transform infrared spectroscopy (FT-IR) confirmed successful modification. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) revealed that the phosphor surface was smooth after coating, with a uniform and dense inorganic/organic composite layer. Fluorescence spectroscopy and pH analysis demonstrated that all three coated samples exhibited a significant improvement in water resistance, with only a slight reduction in luminescence intensity. Among these, the residual luminescence intensity of the continuously coated samples was 84.2% after 24h of water immersion, significantly higher than the uncoated samples. Finally, the application value of water-based coatings was preliminarily explored in the field of anti-counterfeit coatings by using continuously coated phosphors as fillers.</div></div>","PeriodicalId":19564,"journal":{"name":"Optical Materials","volume":"174 ","pages":"Article 117962"},"PeriodicalIF":4.2,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385384","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}
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