Optical and Quantum Electronics最新文献

{"title":"DFT-based comparative analysis of the physical properties of lead-free double perovskites Cs2XF6 (X = Ni, Pd, and Pt)","authors":"Md. Shahidul Islam,&nbsp;M. S. Ali,&nbsp;Md. Tanvir Ahmed,&nbsp;Ahmad Irfan,&nbsp;Md. Atikur Rahman","doi":"10.1007/s11082-026-09154-y","DOIUrl":"10.1007/s11082-026-09154-y","url":null,"abstract":"<div><p>First-principles DFT replications using CASTEP were employed to study the physical properties of lead-free double perovskites Cs₂XF₆ (<i>X</i> = Ni, Pd, and Pt). The calculated values of Goldschmidt tolerance and octahedral factors confirm the structural stability, the negative cohesive energy per atom ensures the thermodynamical stability and the negative formation energies per atom indicate the chemically stable nature of Cs₂XF₆ (<i>X</i> = Ni, Pd, and Pt) compounds. Besides, the phonon calculations confirm the dynamical stability of all compounds, as no imaginary modes are observed. Since their elastic stiffness and tetragonal shear constants are positive, these compounds satisfy the necessities for mechanical and dynamical constancy. The Pugh’s ratio, Frantesvich ratio, Poisson’s ratio, and Cauchy pressure conditions suggest the ductility nature of the Cs₂NiF₆, Cs₂PtF₆ compounds whereas the Cs₂PdF₆ material shows brittle in nature. Owing to its lower Kleinman parameter, the Cs₂PtF₆ compound shows a greater bond stretching/constricting involvement to repelling exterior stress than Cs₂NiF₆, and Cs₂PdF₆. Anisotropy was found in every case based on the tensor analysis, while isotropy appeared only in the linear compressibility. According to the band structure analysis the compounds Cs₂NiF₆, Cs₂PdF₆ and Cs₂PtF₆ exhibit semiconducting manner with indirect band gaps. The estimated band gaps of the examined materials fall within the 1.75 eV-4.15 eV ranges which rendering them useful for optoelectronic technologies. All the compounds show covalent bonding, according to the analysis of Mulliken bond populations. It is clear from the optical properties that the present compounds will be applied as excellent coating materials to reduce solar heating in UV energy regions. All the studied compounds exhibit very low minimum thermal conductivity and low Debye temperatures, indicating their probable use in thermal-barrier-coating (TBC) materials.</p></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 12","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vernier‑cavity erbium fiber laser for broadband C and L‑band single‑longitudinal-mode output","authors":"Zi-Gang Huang,&nbsp;Nai-Yi Lu,&nbsp;Chien-Hung Yeh,&nbsp;Chen-I Tsai,&nbsp;I-Li Chen,&nbsp;Wei-Cheng Lin,&nbsp;Chun-Jin Yang,&nbsp;Bo-Xiang Wu","doi":"10.1007/s11082-026-09166-8","DOIUrl":"10.1007/s11082-026-09166-8","url":null,"abstract":"<div><p>In this paper, an erbium‑doped fiber (EDF) laser employing a quad‑ring resonator scheme is experimentally demonstrated to achieve stable, wavelength‑selectable single‑longitudinal‑mode (SLM) output. By utilizing C‑ and L‑band erbium‑doped fiber amplifiers (EDFAs) as gain media, the proposed fiber laser provides continuous tuning range from 1518.0 to 1612.0 nm. The quad‑ring configuration, based on the Vernier effect, effectively suppresses dense multi-mode oscillations, yielding narrow linewidths of 312.5 Hz, output powers between − 17.4 and − 1.7 dBm, and OSNRs of 33.4 to 70.5 dB. Moreover, the output fluctuations remain below 0.9 dB in power and 0.04 nm in wavelength over 60 min, confirming the laser’s capability to deliver broad tunability, high stability, narrow linewidth, and strong spectral purity.</p></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 12","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SCAPS-1D analysis of interface engineering and performance optimization in an FTO/ZnO/WO₃/CuO/Pt oxide heterojunction solar cell","authors":"Hadja Fatima Mehnane,&nbsp;Mohamed Seddar Yagoub,&nbsp;Mohammed Adnane","doi":"10.1007/s11082-026-09159-7","DOIUrl":"10.1007/s11082-026-09159-7","url":null,"abstract":"<div><p>The simulation of the performance and loss mechanisms of the FTO/ZnO/WO₃/CuO/Pt oxide heterostructure was conducted using the SCAPS-1D where WO₃ serves as an interfacial buffer layer between the Electron Transporting layer ETL ZnO and CuO the absorber layer. By choosing the electron affinity of 3.8 eV for WO₃ and 4.0 eV for CuO from the conducted simulation and literature, it is possible to achieve a moderately small conduction-band offset between WO₃ and CuO. As the comparison of interface defects shows, the defect densities at both the interfaces significantly differ from each other. An increase in the density of interface defects in the CuO/WO₃ interface from 10¹⁰ to 10¹⁶ cm⁻² decreases the efficiency from 19.30% to 0.76%, whereas at the ZnO/WO₃ interface it leads to approximately 1% reduction. Hence, the interface CuO/WO₃ interface becomes the dominating one in terms of the recombination rate. In terms of WO₃ thickness, there exists an optimum value in the range of 30–40 nm, which is determined by the interplay between interfacial carrier transport, depletion region properties, and optical losses. In order to increase the experimental accuracy of the simulation results, the density of defects of bulk CuO and parasitic resistances were taken from experimentally justified values instead of ideal. For CuO defects density 1.5–2×10¹⁴ cm⁻³, Rs = 2 Ω·cm², Rsh = 10⁵ Ω·cm², the efficiency is 18.55%, which is very close to the reference case efficiency of 18.51%. The density of defects of the CuO/WO₃ interface is experimentally undetermined. These results demonstrate the capability of WO₃-based CuO oxides heterostructures, yet the efficiency mentioned above is merely a numerical value.</p></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 12","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uncooled mid-infrared photovoltaic detector based on Pb1−xCdxSe thin films for use in non-dispersive infrared methane gas sensors","authors":"Lewis Fleming,&nbsp;Emma Keel,&nbsp;James Riordan,&nbsp;Carlos Garcia Nunez,&nbsp;Michal Mazur,&nbsp;Des Gibson","doi":"10.1007/s11082-026-09152-0","DOIUrl":"10.1007/s11082-026-09152-0","url":null,"abstract":"<div><p>This work is focussed on sputtered lead cadmium selenide (Pb_1−xCd_xSe) thin films as the active material within high-speed room temperature mid-infrared photovoltaic (PV) detectors for use in non-dispersive infrared gas sensors. Variation of the Cd content provides a means of controlling material bandgap and hence wavelength response. Traditional methods of Pb_1−xCd_xSe deposition are thermal evaporation or chemical bath techniques which do not provide required stable deposition for accurate control of Cd content and hence wavelength response. This paper describes pulsed direct current (DC) sputter deposition of Pb_1−xCd_xSe, from a sintered pre-mixed sputter target as an alternative deposition technique. Sputtered Pb_1−xCd_xSe material characterisation is described identifying optimum Cd content as x = 0.1 for maximised response at a wavelength of 3.3 μm, matching use as a detector for methane gas detection. Work has focussed on characterising pulsed DC sputter deposition of the 3.3 μm optimised Pb_0.9Cd_0.1Se (n-type) and post deposition oxygen doping by thermal diffusion to create p-type Pb_0.9Cd_0.1Se: O thereby maximising PV detector photo-response at a specific wavelength of 3.3 μm. PV detector design, associated photolithographic mask designs/ lift-off process sequence, sputter deposition of Pb_1−xCd_xSe and Ti interdigitated electrodes for PV detector fabrication is described. The resulting 1 × 1 mm² PV detector device exhibited a peak detectivity D* of 1 × 10¹⁰, 4 × 10⁹ and 3 × 10⁹ cm∙Hz^1/2∙W⁻¹ at 233 K, 298 K and 313 K respectively under 500 K blackbody illumination.</p></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 12","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11082-026-09152-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149027640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of lanthanum incorporation on the structure, optical, thermal, dielectric, and nonlinear optical properties of tristhiourea zinc(II) sulphate single crystals","authors":"Bincy Susan Jacob,&nbsp;R. Krishnamurthy,&nbsp;Seenuvasan Karthikayini,&nbsp;Vilvanathan Sathish,&nbsp;Kunasekaran Kadambanathan","doi":"10.1007/s11082-026-09155-x","DOIUrl":"10.1007/s11082-026-09155-x","url":null,"abstract":"<div><p>Pure and 1 mol% lanthanum-doped tristhiourea zinc(II) sulphate (ZTS) single crystals were successfully grown by the slow evaporation solution growth technique to investigate the influence of rare-earth doping on the structure–property relationship of this promising semi-organic nonlinear optical material. Structural analysis by single-crystal X-ray diffraction confirmed that both crystals crystallize in the orthorhombic non-centrosymmetric Pca2₁ space group, while slight variations in the lattice parameters indicate successful incorporation of lanthanum without altering the crystal structure. Powder X-ray diffraction further revealed improved crystallinity and dopant-induced lattice modification. FTIR and FT-Raman spectroscopy confirmed the characteristic vibrational modes of ZTS and suggested subtle changes in the local bonding environment following lanthanum incorporation. UV–Visible analysis demonstrated excellent optical transparency with a lower cut-off wavelength below 290 nm, while the optical band gap increased from 5.2 to 5.5 eV after doping. Thermal analysis showed enhanced thermal stability, with the melting temperature increasing from 239.1 to 246.0 ℃. Dielectric measurements indicated improved polarization behavior with low dielectric loss, whereas microhardness studies revealed reverse indentation size effect characteristics, classifying both crystals as soft materials. The lanthanum-doped crystal exhibited a significantly enhanced second harmonic generation output (4.4 mJ) compared with pure ZTS (2.8 mJ), corresponding to an approximately 57% enhancement in SHG output and an SHG efficiency of approximately 1.9 times that of KDP. The results suggest that localized lattice modification induced by lanthanum incorporation enhances the multifunctional properties of ZTS while preserving its non-centrosymmetric crystal structure, demonstrating the potential of rare-earth doping for developing high-performance nonlinear optical materials for advanced photonic applications.</p></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 11","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and DFT investigation of the structure-property relationship and third-order nonlinear optical response of a halogenated pyridine-based Cd(II) complex","authors":"İrem Furuncuoğlu,&nbsp;Merve Şimşek,&nbsp;Ömer Tamer,&nbsp;Davut Avcı,&nbsp;Yusuf Atalay,&nbsp;Necmi Dege","doi":"10.1007/s11082-026-09160-0","DOIUrl":"10.1007/s11082-026-09160-0","url":null,"abstract":"<div><p>A novel halogen-substituted mixed-ligand Cd(II) coordination complex based on 6-chloro-5-fluoropyridine-2-carboxylate and 1,10-phenanthroline was synthesized and investigated using combined experimental and theoretical methods. Single-crystal X-ray diffraction revealed a dinuclear distorted octahedral structure, while Hirshfeld analysis indicated that H···H and C···H interactions play important roles in crystal stabilization. Density functional theory calculations showed that complex formation reduced the HOMO-LUMO energy gap to 4.5650 eV and increased chemical softness, facilitating intramolecular charge transfer. The direct optical energy gap obtained from the Tauc plot was 4.33 eV, showing reasonable agreement with the theoretical HOMO-LUMO gap. Frontier molecular orbital analysis confirmed ligand-to-ligand charge transfer from the pyridine-based donor to the phenanthroline acceptor. Although the static first hyperpolarizability of the complex was relatively modest (β = 4.6592 × 10^− 30 esu) the static second hyperpolarizability (γ = 219.68 × 10^− 36 esu) was markedly higher than those of the free ligands, indicating an enhanced molecular third-order nonlinear optical response upon complexation. At 532 nm, the calculated dynamic first hyperpolarizability β(-ω;ω,0) = 4.2084 × 10^− 30 esu and the dc-Kerr second hyperpolarizability γ(-ω;ω,0,0) = 259.30 × 10^− 36 esu provided a near-wavelength molecular reference for the 514 nm Z-scan experiment. Z-scan measurements confirmed strong nonlinear absorption (β = 98.9868 × 10^− 5 m/W) and a negative nonlinear refractive index (n₂=-0.8517 × 10^− 13 m²/W), corresponding to χ⁽³⁾ = 90.2437 × 10^− 4 esu. These results support the potential of this Cd(II) complex for third-order nonlinear optical and photonic applications.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 11","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine-learning-assisted loss prediction and analysis of photonic lantern MUX/DEMUX for SDM systems","authors":"Khaoula Aguech,&nbsp;Amine Ben Salem,&nbsp;D. S. Citrin,&nbsp;Mourad Menif","doi":"10.1007/s11082-026-09132-4","DOIUrl":"10.1007/s11082-026-09132-4","url":null,"abstract":"<div><p>Photonic lanterns (PLs) are pivotal passive components for mode-division multiplexing (MDM) in space-division multiplexed (SDM) optical interconnects, enabling low-loss, adiabatic coupling between multiple single-mode and multimode fiber. However, their design relies on computationally intensive full-wave electromagnetic solvers, such as the finite-element method (FEM), beam propagation method (BPM), and finite-difference time-domain (FDTD), which hinder efficient multi-objective optimization across high-dimensional parameter spaces. To overcome this bottleneck, we propose an XGBoost-based supervised surrogate modeling framework for simultaneous prediction of insertion loss (IL), mode-dependent loss (MDL), and polarization-dependent loss (PDL), trained on a physics-validated 2,000-sample FEM dataset spanning seven multicore geometries across the full C-band (1530–1590 nm). The surrogate achieves <span>(R^2&gt; 0.98)</span>, <span>(textrm{RMSE} &lt; 0.13,textrm{dB})</span>, and <span>(textrm{MAE} &lt; 0.075,textrm{dB})</span> across all three targets, reducing per-design evaluation time from <span>(sim 6.8,textrm{h})</span> (FEM/BPM) to <span>(&lt;1,textrm{ms})</span>—a speedup of <span>(sim 2.45 times 10^{7})</span>—while maintaining sub-<span>(0.1,textrm{dB})</span> spectral stability across the full C-band. This capability enables rapid parametric sweeps of PL configurations in under <span>(10,textrm{s})</span>, supporting automated multi-objective optimization for MIMO-free MDM intra-data-center links at link lengths below <span>(2,textrm{km})</span>.</p></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 11","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11082-026-09132-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling of optical properties in asymmetric elliptical nanotubes under external electric field","authors":"V. Holovatsky,&nbsp;N. Holovatska,&nbsp;I. Shakun","doi":"10.1007/s11082-026-09162-y","DOIUrl":"10.1007/s11082-026-09162-y","url":null,"abstract":"<div><p>This paper theoretically investigates the effects of geometric asymmetry and an external static electric field on the energy spectrum and dimensionless oscillator strengths of electron intersubband transitions in a GaAs nanotube with an elliptical outer surface and an eccentrically positioned cylindrical inner surface. The energy spectrum and electron wave functions are obtained within the effective mass approximation using the finite element method. It is shown that increasing the outer-surface ellipticity leads to two electron localization regions, removes the degeneracy of excited states, and produces an accidental quasi-degeneracy of the ground and first excited states, substantially modifying transition probabilities and enhancing transitions to higher-energy states. The electric field and structural eccentricity modify the energy spectrum and induce anticrossing regions. It is demonstrated that a compensating electric field restores the quasi-degeneracy of the ground and first excited states, accompanied by abrupt changes in the most probable transition energies. The optical properties exhibit pronounced polarization anisotropy: the most probable intersubband transitions induced by x-polarized light have energies approximately twice those induced by y-polarized light. These results demonstrate the possibility of tuning the electronic and optical properties of elliptical nanotubes through geometric design and external electric fields for optoelectronic applications.</p></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 11","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149034470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic effects of CdO and Fe2O3 on structural, optical, and radiation shielding properties of zinc sodium phosphate glass","authors":"Hytham A. Abd El-Ghany,&nbsp;Hosam M. G. Al-Qatlawi","doi":"10.1007/s11082-026-09135-1","DOIUrl":"10.1007/s11082-026-09135-1","url":null,"abstract":"<div><p>The present study investigates the influence of CdO and Fe₂O₃ incorporation on the structural, optical, and gamma-ray shielding properties of zinc sodium phosphate glass with the composition 43P₂O₅–(40 − x)ZnO–17Na₂O–xY (Y = CdO or Fe₂O₃, x = 3 mol%). X-ray diffraction (XRD) confirmed that all prepared samples retained their amorphous structure after doping. The glass density increased from 2.953 g cm⁻³ for the undoped sample to 3.161 g cm^− 3 and 3.254 g cm^− 3 after CdO and FeO₃ addition, respectively, indicating enhanced structural compactness. UV–Vis spectroscopy revealed that both dopants reduced the optical transparency window and decreased the direct optical band gap from 5.30 eV to 4.63 eV, while the indirect band gap decreased from 3.59 eV to 3.31 eV, with the Fe₂O₃-doped glass exhibiting the strongest UV absorption. The optical quality factor analysis showed that the undoped glass possessed the highest optical quality throughout most of the investigated spectral range, whereas Fe₂O₃ doping promoted stronger photon interaction. Gamma-ray shielding parameters were evaluated using the XCOM database at 0.662 MeV. The linear attenuation coefficient increased from 0.1095 cm^− 1 for the undoped glass to 0.1227 cm^− 1 for the Fe₂O₃₋containing glass, while the half-value layer decreased from 6.33 cm to 5.65 cm. These improvements demonstrate that Fe₂O₃ is more effective than CdO in enhancing both optical attenuation and radiation shielding performance. The obtained results indicate that Fe₂O₃-doped zinc sodium phosphate glass is a promising candidate for optical filters, UV-protective windows, and gamma-radiation shielding applications.</p></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 11","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148986693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bifunctional CuO thin films: tuning antibacterial and photocatalytic performance through precursor molarity by spray pyrolysis","authors":"Mouad Chettab,&nbsp;Halima Djaaboube,&nbsp;Yassine Bouachiba,&nbsp;Safia Harrat,&nbsp;Adel Taabouche,&nbsp;Redha Aouati,&nbsp;Sihem Abed,&nbsp;Ouidad Abdelaziz","doi":"10.1007/s11082-026-09142-2","DOIUrl":"10.1007/s11082-026-09142-2","url":null,"abstract":"<div><p>Copper oxide (CuO) thin films were successfully deposited by spray pyrolysis using precursor solutions with different molarities (0.02, 0.05 and 0.1 M) in order to investigate the correlation between growth conditions and multifunctional properties. Structural analysis confirmed the formation of monoclinic CuO with improved crystallinity as the molarity increased. The crystallite size increased to <span>(sim )</span> 17 nm while the strain and dislocation density decreased, indicating enhanced crystal quality at higher precursor concentrations. In FTIR spectra, it was observed that the bonding at 400 and 402 cm⁻¹ which attributed to Cu–O stretching bonds which confirms the formation of CuO phase. Surface morphology analysis showed that higher molarity led to increased roughness and grain size to <span>(sim )</span> 61 nm and <span>(sim )</span> 1.9 <span>(times )</span> 10⁵ nm² respectively, reflecting a smoother and more homogeneous surface. Optical studies revealed a decrease in optical bandgap to 1.41 eV at 0.1 M. The Urbach energy increased to 0.89 eV at the same molarity indicating a low disorder and defect density in the films. Electrical measurements demonstrated a significant enhancement in conductivity with increasing molarity reaching to 7.88 × 10¹³ cm⁻³, driven by the combined effect of higher carrier concentration and improved mobility due to reduced grain boundary scattering. Photocatalytic performance evaluated through methylene blue (MB) degradation under natural sunlight revealed that the 0.02 M film exhibited the highest degradation efficiency ~70.21%, which is attributed to its higher surface area ~ 67.91 m² /g and greater density of active sites. In contrast, antibacterial activity tests showed that films prepared at higher molarity 0.1 M exhibited superior bactericidal performance, particularly against Gram-negative bacteria, due to enhanced Cu²⁺ ion release and increased generation of reactive oxygen species (ROS). These findings demonstrate a clear trade-off between photocatalytic and antibacterial performance, governed by precursor molarity. The study highlights molarity control as a simple and effective strategy for tailoring CuO thin films toward eco-friendly multifunctional applications in environmental remediation and antimicrobial coatings.</p></div>","PeriodicalId":720,"journal":{"name":"Optical and Quantum Electronics","volume":"58 11","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148987029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}