Pub Date : 2025-12-01Epub Date: 2025-10-29DOI: 10.1016/j.apsadv.2025.100889
Liping Liao, Ting Liu, Daiying Yuan
NiCr-based coatings are widely used in high-temperature systems such as aeroengines and gas turbines; however, their fundamental nanoscale tribological mechanisms remain inadequately resolved. Here, molecular dynamics simulations were employed to investigate Ni1-xCrx alloys (x = 10, 15, 20, 25, and 30 at.%) over a temperature range of 300–1200 K. The results show that frictional forces decrease by ∼43 % with increasing temperature and by ∼31 % with higher Cr concentration. Atomic-scale wear analysis reveals that elevated temperatures accelerate material degradation, while Cr addition mitigates wear accumulation. Thermal softening and localized amorphization at high temperatures contribute to more symmetric pile-up morphologies and a stabilized frictional response. Furthermore, increased Cr content enhances defect-mediated plasticity, thereby reducing interfacial resistance. These findings clarify the coupled influence of temperature and composition on nanoscale wear, offering atomistic insights to inform the design and optimization of NiCr coatings for high temperature environments.
{"title":"A molecular dynamics study of high-temperature tribological characteristics of NiCr coatings","authors":"Liping Liao, Ting Liu, Daiying Yuan","doi":"10.1016/j.apsadv.2025.100889","DOIUrl":"10.1016/j.apsadv.2025.100889","url":null,"abstract":"<div><div>NiCr-based coatings are widely used in high-temperature systems such as aeroengines and gas turbines; however, their fundamental nanoscale tribological mechanisms remain inadequately resolved. Here, molecular dynamics simulations were employed to investigate Ni<sub>1-x</sub>Cr<sub>x</sub> alloys (<em>x</em> = 10, 15, 20, 25, and 30 at.%) over a temperature range of 300–1200 K. The results show that frictional forces decrease by ∼43 % with increasing temperature and by ∼31 % with higher Cr concentration. Atomic-scale wear analysis reveals that elevated temperatures accelerate material degradation, while Cr addition mitigates wear accumulation. Thermal softening and localized amorphization at high temperatures contribute to more symmetric pile-up morphologies and a stabilized frictional response. Furthermore, increased Cr content enhances defect-mediated plasticity, thereby reducing interfacial resistance. These findings clarify the coupled influence of temperature and composition on nanoscale wear, offering atomistic insights to inform the design and optimization of NiCr coatings for high temperature environments.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100889"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145417646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-09-27DOI: 10.1016/j.apsadv.2025.100865
Jianping Gao , Xing Wang , Kai Liu , Jing Ning , Yuanjiang Lv , Junda Chen , Yang Wang , Fei Ma
High corrosion resistance, high electrical conductivity and strong interface adhesion on Ti substrate are fundamental requirements for the coatings on bipolar plates (BPs) of proton exchange membrane water electrolysis (PEMWE). In this work, TiONx/TiN composite coatings on Ti BPs with a small lattice mismatch of only 1.37% are prepared through anodizing and then in-situ plasma nitriding for TiONx and magnetron sputtering for TiN. The lattice mismatch is remarkably smaller than that between TiO2 and TiN (8.88%). The small lattice mismatch and the in-situ grown on Ti BPs could ensure the strong interface adhesion strength of the TiONx/TiN coating at level 0 (ISO 2409:2007). Moreover, commonly, TiONx exhibits good corrosion resistance, while TiN displays high electrical conductivity. Accordingly, the composite coatings exhibit enhanced corrosion resistance (0.17 μA·cm-2) and high electrical conductivity (6.75 mΩ·cm2 at 1.5 MPa). After 300 h of potentiostatic test at 2 V, the TiONx/TiN coating maintains a low corrosion current density of 4.6 μA·cm-2 and interface contact resistance (ICR) of 23.64 mΩ·cm2. In cell assembly test, the TiONx/TiN-coated BP exhibits lower ICR and higher electrolysis efficiency (77.89%) than uncoated BPs (64.35%). Overall, the TiONx/TiN coating prepared through anodizing and then in-situ plasma nitriding might be potential candidates for protecting Ti BPs of PEMWE.
{"title":"Synergistically enhanced corrosion resistance, electrical conductivity and interface adhesion of TiONx/TiN coatings through in-situ anodizing and plasma nitriding of Ti BPs for PEMWE cells","authors":"Jianping Gao , Xing Wang , Kai Liu , Jing Ning , Yuanjiang Lv , Junda Chen , Yang Wang , Fei Ma","doi":"10.1016/j.apsadv.2025.100865","DOIUrl":"10.1016/j.apsadv.2025.100865","url":null,"abstract":"<div><div>High corrosion resistance, high electrical conductivity and strong interface adhesion on Ti substrate are fundamental requirements for the coatings on bipolar plates (BPs) of proton exchange membrane water electrolysis (PEMWE). In this work, TiON<sub>x</sub>/TiN composite coatings on Ti BPs with a small lattice mismatch of only 1.37% are prepared through anodizing and then in-situ plasma nitriding for TiON<sub>x</sub> and magnetron sputtering for TiN. The lattice mismatch is remarkably smaller than that between TiO<sub>2</sub> and TiN (8.88%). The small lattice mismatch and the in-situ grown on Ti BPs could ensure the strong interface adhesion strength of the TiON<sub>x</sub>/TiN coating at level 0 (ISO 2409:2007). Moreover, commonly, TiON<sub>x</sub> exhibits good corrosion resistance, while TiN displays high electrical conductivity. Accordingly, the composite coatings exhibit enhanced corrosion resistance (0.17 μA·cm<sup>-2</sup>) and high electrical conductivity (6.75 mΩ·cm<sup>2</sup> at 1.5 MPa). After 300 h of potentiostatic test at 2 V, the TiON<sub>x</sub>/TiN coating maintains a low corrosion current density of 4.6 μA·cm<sup>-2</sup> and interface contact resistance (ICR) of 23.64 mΩ·cm<sup>2</sup>. In cell assembly test, the TiON<sub>x</sub>/TiN-coated BP exhibits lower ICR and higher electrolysis efficiency (77.89%) than uncoated BPs (64.35%). Overall, the TiON<sub>x</sub>/TiN coating prepared through anodizing and then in-situ plasma nitriding might be potential candidates for protecting Ti BPs of PEMWE.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100865"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-21DOI: 10.1016/j.apsadv.2025.100881
Marion Stalet , Sara Hélis , Laurence Convert , Rémi Dreyfus , Jean-François Bryche , Loïc Leroy , Paul G. Charette , Michael Canva , Yoann Roupioz
The intricate interaction between bacteria and surfaces, coupled with the complexity of biofilm formation, poses significant challenges in understanding and controlling microbial behaviour. To combat pathogen contamination and proliferation, bioinspired nanostructures as antimicrobial surfaces have gained prominence over the past decade. However, conflicting theoretical studies and experimental results have made it difficult to draw general conclusions about antibacterial mechanisms. To address these challenges, we have adopted an approach that provides access to deeper insights to characterize the performance of surfaces, by taking into account different modes of antibacterial action. To demonstrate the applicability of this strategy, nanostructured materials mimicking dragonfly wing, were evaluated. A gold electrodeposition process was optimized to create large-area, uniform nanospike arrays, ranging in height from 70 to 570 nm. Large sample area (12 cm²) was critical for ensuring statistically significant results in the analysis of antibacterial effects. Model surfaces with ∼150 nm high spikes were tested, demonstrating significant efficacy in reducing bacterial proliferation for Escherichia coli and Staphylococcus epidermidis. Moreover, striking differences between strains were observed in biofouling (surface detachment and release of bacteria). These findings underscore the relevance of such a protocol in precisely characterizing bacterial interactions with antimicrobial materials. By providing a standardized characterization method, this study aims to facilitate a deeper understanding of antimicrobial surface interactions with bacteria and contributes to the development of more effective antibacterial surfaces.
{"title":"Unraveling the complexity of surface antibacterial effects: A multifaceted evaluation of electrodeposited nanospikes","authors":"Marion Stalet , Sara Hélis , Laurence Convert , Rémi Dreyfus , Jean-François Bryche , Loïc Leroy , Paul G. Charette , Michael Canva , Yoann Roupioz","doi":"10.1016/j.apsadv.2025.100881","DOIUrl":"10.1016/j.apsadv.2025.100881","url":null,"abstract":"<div><div>The intricate interaction between bacteria and surfaces, coupled with the complexity of biofilm formation, poses significant challenges in understanding and controlling microbial behaviour. To combat pathogen contamination and proliferation, bioinspired nanostructures as antimicrobial surfaces have gained prominence over the past decade. However, conflicting theoretical studies and experimental results have made it difficult to draw general conclusions about antibacterial mechanisms. To address these challenges, we have adopted an approach that provides access to deeper insights to characterize the performance of surfaces, by taking into account different modes of antibacterial action. To demonstrate the applicability of this strategy, nanostructured materials mimicking dragonfly wing, were evaluated. A gold electrodeposition process was optimized to create large-area, uniform nanospike arrays, ranging in height from 70 to 570 nm. Large sample area (12 cm²) was critical for ensuring statistically significant results in the analysis of antibacterial effects. Model surfaces with ∼150 nm high spikes were tested, demonstrating significant efficacy in reducing bacterial proliferation for <em>Escherichia coli</em> and <em>Staphylococcus epidermidis</em>. Moreover, striking differences between strains were observed in biofouling (surface detachment and release of bacteria). These findings underscore the relevance of such a protocol in precisely characterizing bacterial interactions with antimicrobial materials. By providing a standardized characterization method, this study aims to facilitate a deeper understanding of antimicrobial surface interactions with bacteria and contributes to the development of more effective antibacterial surfaces.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100881"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work aimed to synthesize new magnetic nanocomposites from pistachio green hull biochar (PGHB) and compare their ability to eliminate the cationic dye of methylene blue (MB) and the antibiotic tetracycline (TC) from water and industrial wastewater. The properties of PGHB, PGHB/CoFe₂O₄, and PGHB/CoFe₂O₄/UiO-66@polydopamine (PDA) magnetic nanocomposite were measured using SEM, FT-IR, VSM, AFM, Raman, BET, and XRD. The results showed successful synthesis of the magnetic nanocomposites and enhanced structural properties of PGHB after modification with CoFe₂O₄ and UiO-66@PDA nanoparticles. The specific surface area of PGHB, PGHB/CoFe₂O₄, and PGHB/CoFe₂O₄/UiO-66@PDA was 32.428, 97.637, and 428.080 m²/g, respectively, indicating improved surface area upon modification. The saturation magnetization (Ms) of PGHB/CoFe₂O₄ and PGHB/CoFe₂O₄/UiO-66@PDA was 36.860 and 23.648 emu/g, respectively, confirming their easy recovery from aqueous solutions with a magnet. Parameters influencing MB and TC removal indicated that increasing contact time and adsorbent mass enhanced the sorption efficiency, while higher temperature and initial pollutant concentration reduced it. Maximum removal efficiency of MB (98.87 %) and TC (99.12 %) was achieved using PGHB/CoFe₂O₄/UiO-66@PDA nanocomposites at pH 10 and 6, respectively, at 25 °C, 0.8 g/L adsorbent mass, 10 mg/L initial concentration, and 50 min contact time. Thermodynamic results showed exothermic sorption, with spontaneous processes indicated by negative Gibbs free energy. Adsorption followed the Freundlich isotherm model, confirming heterogeneous and multilayer sorption. Kinetic studies followed the pseudo-second-order model, indicating chemical sorption. The magnetic nanocomposites demonstrated excellent reusability for multiple cycles and effectively reduced BOD₅, COD, and TOC in industrial wastewater.
{"title":"Removal of tetracycline and methylene blue using pistachio green hull biochar (PGHB), magnetic PGHB/CoF2O4, and magnetic nanocomposite PGHB/CoFe2O4/UiO-66@polydopamine","authors":"Rauf Foroutan , Mahsa Foroughi , Abolfazl Tutunchi , Bahman Ramavandi","doi":"10.1016/j.apsadv.2025.100876","DOIUrl":"10.1016/j.apsadv.2025.100876","url":null,"abstract":"<div><div>This work aimed to synthesize new magnetic nanocomposites from pistachio green hull biochar (PGHB) and compare their ability to eliminate the cationic dye of methylene blue (MB) and the antibiotic tetracycline (TC) from water and industrial wastewater. The properties of PGHB, PGHB/CoFe₂O₄, and PGHB/CoFe₂O₄/UiO-66@polydopamine (PDA) magnetic nanocomposite were measured using SEM, FT-IR, VSM, AFM, Raman, BET, and XRD. The results showed successful synthesis of the magnetic nanocomposites and enhanced structural properties of PGHB after modification with CoFe₂O₄ and UiO-66@PDA nanoparticles. The specific surface area of PGHB, PGHB/CoFe₂O₄, and PGHB/CoFe₂O₄/UiO-66@PDA was 32.428, 97.637, and 428.080 m²/g, respectively, indicating improved surface area upon modification. The saturation magnetization (Ms) of PGHB/CoFe₂O₄ and PGHB/CoFe₂O₄/UiO-66@PDA was 36.860 and 23.648 emu/g, respectively, confirming their easy recovery from aqueous solutions with a magnet. Parameters influencing MB and TC removal indicated that increasing contact time and adsorbent mass enhanced the sorption efficiency, while higher temperature and initial pollutant concentration reduced it. Maximum removal efficiency of MB (98.87 %) and TC (99.12 %) was achieved using PGHB/CoFe₂O₄/UiO-66@PDA nanocomposites at pH 10 and 6, respectively, at 25 °C, 0.8 g/L adsorbent mass, 10 mg/L initial concentration, and 50 min contact time. Thermodynamic results showed exothermic sorption, with spontaneous processes indicated by negative Gibbs free energy. Adsorption followed the Freundlich isotherm model, confirming heterogeneous and multilayer sorption. Kinetic studies followed the pseudo-second-order model, indicating chemical sorption. The magnetic nanocomposites demonstrated excellent reusability for multiple cycles and effectively reduced BOD₅, COD, and TOC in industrial wastewater.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100876"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145333875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-11-11DOI: 10.1016/j.apsadv.2025.100901
Mohammad Arab, Akbar Eshaghi, Ehsan Mohammad Sharifi
CZTS (Cu2ZnSnS4) kesterite-based solar cells represent promising low-cost and eco-friendly alternatives to traditional solar technologies. While CZTS absorber layers exhibit notable optical advantages, their solar cell efficiency remains below 15 %. One strategy to enhance the optical performance of these layers is doping with alkaline earth metals. This study systematically investigates the calcium incorporation in CZTS thin films synthesized via the cost-effective spray pyrolysis technique. In this study, an attempt has been made to investigate the optical behavior of CZTS layers doped with 1 % to 4 % by weight of calcium. Thin CZTS layers were initially deposited onto the SLG surface using pneumatic spray pyrolysis, followed by annealing in a sulfur vapor and argon atmosphere. The deposited thin films were subsequently characterized by XRD, AFM, FESEM, EDX, DRS, FTIR, and Raman spectroscopy techniques. The results indicate that increasing calcium doping up to 4 % enhances the effective absorption of CZTS thin films in the visible spectrum. Additionally, calcium doping reduces the band gap of the CZTS absorber, reaching 1.41 eV at a 4 % Ca concentration. The increase in optical conductivity with higher Ca doping suggests that calcium improves the optical response of CZTS thin films. Structural analysis confirms that the thin films are well-formed in the kesterite structure. Surface morphology analysis indicates that as calcium doping increases, surface roughness also rises. This increase in roughness could enhance photon absorption but may adversely affect the interface between the absorber and buffer layers.
{"title":".Effect of calcium substitutional doping on the structural and optical properties of kesterite Cu2ZnSnS4 thin films","authors":"Mohammad Arab, Akbar Eshaghi, Ehsan Mohammad Sharifi","doi":"10.1016/j.apsadv.2025.100901","DOIUrl":"10.1016/j.apsadv.2025.100901","url":null,"abstract":"<div><div>CZTS (Cu<sub>2</sub>ZnSnS<sub>4</sub>) kesterite-based solar cells represent promising low-cost and eco-friendly alternatives to traditional solar technologies. While CZTS absorber layers exhibit notable optical advantages, their solar cell efficiency remains below 15 %. One strategy to enhance the optical performance of these layers is doping with alkaline earth metals. This study systematically investigates the calcium incorporation in CZTS thin films synthesized via the cost-effective spray pyrolysis technique. In this study, an attempt has been made to investigate the optical behavior of CZTS layers doped with 1 % to 4 % by weight of calcium. Thin CZTS layers were initially deposited onto the SLG surface using pneumatic spray pyrolysis, followed by annealing in a sulfur vapor and argon atmosphere. The deposited thin films were subsequently characterized by XRD, AFM, FESEM, EDX, DRS, FTIR, and Raman spectroscopy techniques. The results indicate that increasing calcium doping up to 4 % enhances the effective absorption of CZTS thin films in the visible spectrum. Additionally, calcium doping reduces the band gap of the CZTS absorber, reaching 1.41 eV at a 4 % Ca concentration. The increase in optical conductivity with higher Ca doping suggests that calcium improves the optical response of CZTS thin films. Structural analysis confirms that the thin films are well-formed in the kesterite structure. Surface morphology analysis indicates that as calcium doping increases, surface roughness also rises. This increase in roughness could enhance photon absorption but may adversely affect the interface between the absorber and buffer layers.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100901"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145525717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-08DOI: 10.1016/j.apsadv.2025.100870
Sadoon Farrukh, Jaroslav Vlček, Jiří Rezek, Jiří Houška, Radomír Čerstvý, Tomáš Kozák
We report the crystal structure, surface morphology, electronic band structure, optical and electrical properties, and semiconductor-metal transition characteristics of strongly thermochromic W-doped VO2 films with a large (up to -16 % K−1) temperature coefficient of electrical resistance at a small hysteresis width of electrical resistivity (down to 3 °C) near room temperature, and with a wide temperature operation range at a high detection sensitivity (≥ 8 % K−1) and low values of the electrical resistivity. They were deposited at a reduced substrate temperature of 350 °C onto soda-lime glass (SLG) with two versions of yttria-stabilized zirconia (YSZ) interlayers possessing different cubic crystal orientations, and onto bare SLG and monocrystalline YSZ and Al2O3 substrates for comparison. The W-doped VO2 depositions were performed using reactive deep oscillation magnetron sputtering with a feedback pulsed O2 flow control allowing us to increase deposition rate of films up to 20–30 nm min−1 for a target-substrate distance of 100 mm. The results are important for a further improvement of thermochromic performance of VO2-based coatings for energy-saving smart windows and for a new design of high-performance infrared detectors and temperature sensors prepared by a fast low-temperature scalable synthesis.
我们报道了强热致变色w掺杂VO2薄膜的晶体结构、表面形貌、电子能带结构、光学和电学性能以及半导体-金属转变特性，这些薄膜在室温附近具有较大的电阻温度系数（高达- 16% K−1），电阻率的滞后宽度较小（低至3°C）。温度工作范围宽，检测灵敏度高（≥8% K−1），电阻率低。他们在350°C的降低衬底温度下沉积在具有两种不同立方晶取向的氧化钇稳定氧化锆（YSZ）夹层的钠石灰玻璃（SLG）上，并在裸SLG和单晶YSZ和Al2O3衬底上进行比较。w掺杂VO2的沉积采用反应性深振荡磁控溅射和反馈脉冲O2流量控制进行，使我们能够在目标-衬底距离为100 mm的情况下将薄膜的沉积速率提高到20-30 nm min - 1。研究结果对于进一步提高节能智能窗用vo2基涂层的热致变色性能，以及通过快速低温可扩展合成制备高性能红外探测器和温度传感器具有重要意义。
{"title":"Strongly thermochromic W-doped VO2 films with a large temperature coefficient of electrical resistance near room temperature","authors":"Sadoon Farrukh, Jaroslav Vlček, Jiří Rezek, Jiří Houška, Radomír Čerstvý, Tomáš Kozák","doi":"10.1016/j.apsadv.2025.100870","DOIUrl":"10.1016/j.apsadv.2025.100870","url":null,"abstract":"<div><div>We report the crystal structure, surface morphology, electronic band structure, optical and electrical properties, and semiconductor-metal transition characteristics of strongly thermochromic W-doped VO<sub>2</sub> films with a large (up to -16 % K<sup>−1</sup>) temperature coefficient of electrical resistance at a small hysteresis width of electrical resistivity (down to 3 °C) near room temperature, and with a wide temperature operation range at a high detection sensitivity (≥ 8 % K<sup>−1</sup>) and low values of the electrical resistivity. They were deposited at a reduced substrate temperature of 350 °C onto soda-lime glass (SLG) with two versions of yttria-stabilized zirconia (YSZ) interlayers possessing different cubic crystal orientations, and onto bare SLG and monocrystalline YSZ and Al<sub>2</sub>O<sub>3</sub> substrates for comparison. The W-doped VO<sub>2</sub> depositions were performed using reactive deep oscillation magnetron sputtering with a feedback pulsed O<sub>2</sub> flow control allowing us to increase deposition rate of films up to 20–30 nm min<sup>−1</sup> for a target-substrate distance of 100 mm. The results are important for a further improvement of thermochromic performance of VO<sub>2</sub>-based coatings for energy-saving smart windows and for a new design of high-performance infrared detectors and temperature sensors prepared by a fast low-temperature scalable synthesis.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100870"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145268944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-22DOI: 10.1016/j.apsadv.2025.100879
Salem O. Elhamali , Nikolaos Pliatsikas , James A. Hillier , Wayne M. Cranton , X. Hou , Nikolaos Kalfagiannis , Panos Patsalas , Demosthenes C. Koutsogeorgis
The impact of structural defects on the electrical properties of aluminium doped zinc oxide (AZO) thin films is investigated by varying sputter deposition and post deposition annealing conditions. Results demonstrate sputtered species of high kinetic energy at high radio frequency power (or low sputtering pressure) facilitate the production of AZO films with enhanced crystallinity, grain growth, and compactness with reduced trap defects at grain boundaries. A resistivity of 1.11 × 10–3 Ω.cm is achieved for the optimised as-deposited samples at room temperature (RT), using 3.95 W/cm2 sputtering at 2 mTorr of Ar. Post deposition annealing via pulsed Krypton Fluoride (KrF λ = 248 nm) excimer laser annealing (ELA) and rapid thermal annealing (RTA), provided a functional means to further manipulate the defects in terms of density and distribution. ELA (5 pulses at 125 mJ/cm2 in air) and RTA (300 °C/20 s in nitrogen) resulted in a ∼50 % resistivity reduction to ∼5.20 × 10–4 Ω.cm due to an increase of both free electron density and Hall mobility. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and Hall Effect measurements demonstrated a reduction of structural, adsorbed, and morphological defects, with an enhancement of compactness and the effective incorporation of Al into the ZnO lattice. ELA increased the visible transparency from 82 % to 86 %, and the bandgap (Eg) from 3.69 eV to 3.80 eV. RTA also increased the bandgap to 3.80 eV, with a slightly larger increase in the visible transparency to 88 %. The optimised ELA and RTA procedures present a roadmap of rapid annealing conditions following low temperature deposition suitable for the optoelectronics industry and transparent electrodes applications.
{"title":"Defect engineering and dopant activation of room temperature grown aluminium-doped zinc oxide thin films","authors":"Salem O. Elhamali , Nikolaos Pliatsikas , James A. Hillier , Wayne M. Cranton , X. Hou , Nikolaos Kalfagiannis , Panos Patsalas , Demosthenes C. Koutsogeorgis","doi":"10.1016/j.apsadv.2025.100879","DOIUrl":"10.1016/j.apsadv.2025.100879","url":null,"abstract":"<div><div>The impact of structural defects on the electrical properties of aluminium doped zinc oxide (AZO) thin films is investigated by varying sputter deposition and post deposition annealing conditions. Results demonstrate sputtered species of high kinetic energy at high radio frequency power (or low sputtering pressure) facilitate the production of AZO films with enhanced crystallinity, grain growth, and compactness with reduced trap defects at grain boundaries. A resistivity of 1.11 × 10<sup>–3</sup> Ω.cm is achieved for the optimised as-deposited samples at room temperature (RT), using 3.95 W/cm<sup>2</sup> sputtering at 2 mTorr of Ar. Post deposition annealing via pulsed Krypton Fluoride (KrF <em>λ</em> = 248 nm) excimer laser annealing (ELA) and rapid thermal annealing (RTA), provided a functional means to further manipulate the defects in terms of density and distribution. ELA (5 pulses at 125 mJ/cm<sup>2</sup> in air) and RTA (300 °C/20 s in nitrogen) resulted in a ∼50 % resistivity reduction to ∼5.20 × 10<sup>–4</sup> Ω.cm due to an increase of both free electron density and Hall mobility. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and Hall Effect measurements demonstrated a reduction of structural, adsorbed, and morphological defects, with an enhancement of compactness and the effective incorporation of Al into the ZnO lattice. ELA increased the visible transparency from 82 % to 86 %, and the bandgap (<em>Eg</em>) from 3.69 eV to 3.80 eV. RTA also increased the bandgap to 3.80 eV, with a slightly larger increase in the visible transparency to 88 %. The optimised ELA and RTA procedures present a roadmap of rapid annealing conditions following low temperature deposition suitable for the optoelectronics industry and transparent electrodes applications.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100879"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-11-03DOI: 10.1016/j.apsadv.2025.100890
Elham Sarvari , Mohammadreza Hosseinzadeh , Pegah Bousak , Jan Frenzel , Aslan Ahadi
Potentiodynamic polarization measurements combined with acoustic emission (AE) monitoring and in-situ observations are employed to investigate the electrochemical behavior of a CuAlMn shape memory alloy with different microstructures. While the polarization responses are broadly similar across microstructures, the surface film composition, morphology, damage mechanisms, and associated AE activity show strong sensitivity to microstructural variation. The AE activity linked to the surface film life cycle (initiation/propagation, dissolution, and mechanical degradation) intensifies progressively with increasing microstructural complexity, from single-crystalline to polycrystalline austenitic, to two-phase (α + β), and finally to martensitic structures. Clustering analysis of AE events reveals that film initiation/propagation is dominated by low-energy events spanning a broad frequency range, whereas dissolution emits low-frequency (39 –120 kHz), high-energy signals across microstructures. Severe mechanical degradation occurs in the α + β and martensitic microstructures via interfacial decohesion (at the α/β interface) and micro/macro cracking, respectively, both releasing AE signals around ∼ 250 kHz. Notably, micro/macro cracking in the martensitic microstructure generates AE with peak amplitudes up to 7 mV and energies three orders of magnitude higher than other degradation mechanisms. These findings demonstrate that internal interfaces play a critical role in controlling surface film evolution and highlight AE monitoring as a powerful tool for discriminating corrosion processes across different microstructures.
{"title":"Acoustic emission monitoring of corrosion in CuAlMn shape memory alloys: influence of microstructure","authors":"Elham Sarvari , Mohammadreza Hosseinzadeh , Pegah Bousak , Jan Frenzel , Aslan Ahadi","doi":"10.1016/j.apsadv.2025.100890","DOIUrl":"10.1016/j.apsadv.2025.100890","url":null,"abstract":"<div><div>Potentiodynamic polarization measurements combined with acoustic emission (AE) monitoring and in-situ observations are employed to investigate the electrochemical behavior of a CuAlMn shape memory alloy with different microstructures. While the polarization responses are broadly similar across microstructures, the surface film composition, morphology, damage mechanisms, and associated AE activity show strong sensitivity to microstructural variation. The AE activity linked to the surface film life cycle (initiation/propagation, dissolution, and mechanical degradation) intensifies progressively with increasing microstructural complexity, from single-crystalline to polycrystalline austenitic, to two-phase (<em>α</em> + <em>β</em>), and finally to martensitic structures. Clustering analysis of AE events reveals that film initiation/propagation is dominated by low-energy events spanning a broad frequency range, whereas dissolution emits low-frequency (39 –120 kHz), high-energy signals across microstructures. Severe mechanical degradation occurs in the <em>α</em> + <em>β</em> and martensitic microstructures via interfacial decohesion (at the <em>α/β</em> interface) and micro/macro cracking, respectively, both releasing AE signals around ∼ 250 kHz. Notably, micro/macro cracking in the martensitic microstructure generates AE with peak amplitudes up to 7 mV and energies three orders of magnitude higher than other degradation mechanisms. These findings demonstrate that internal interfaces play a critical role in controlling surface film evolution and highlight AE monitoring as a powerful tool for discriminating corrosion processes across different microstructures.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100890"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-02DOI: 10.1016/j.apsadv.2025.100867
Dae-Hyung Cho , Tae-Ha Hwang , Yong-Duck Chung , Rina Kim , Jaehan Park , Mann-Ho Cho , Woo-Jung Lee
Bismuth selenide (Bi2Se3) is a prototypical topological insulator that exhibits robust surface states with spin-momentum locking and high carrier mobility, making it a key material for quantum and spintronic applications. We systematically investigated the thickness-dependent morphological evolution and quantum transport properties of Bi2Se3 thin films grown by a two-step thermal evaporation method. Films with thicknesses of 3–80 quintuple layers (QL) were deposited under high vacuum and annealed at 200 °C. Ultrathin films (≤ 9 QL) exhibited island-like discontinuous morphology and high resistance, while thicker films (> 9 QL) formed continuous, c-axis-oriented crystalline layers with enhanced smoothness and conductivity. The highest Raman peak intensity was obtained for the 9-QL film due to enhanced electron-phonon coupling, suggesting that 9 QL is the critical thickness for coherent phonon and carrier behavior. Magnetotransport measurements revealed weak antilocalization at low fields and an increasing contribution from bulk transport channels at high fields in thicker films. These findings provide insights into the nucleation-to-coalescence transition of layered Bi2Se3 films and establish 9–40 QL as the optimal thickness range for accessing topological surface transport in quantum devices.
{"title":"Thickness-dependent structural evolution and quantum transport properties of Bi2Se3 thin films grown by thermal evaporation","authors":"Dae-Hyung Cho , Tae-Ha Hwang , Yong-Duck Chung , Rina Kim , Jaehan Park , Mann-Ho Cho , Woo-Jung Lee","doi":"10.1016/j.apsadv.2025.100867","DOIUrl":"10.1016/j.apsadv.2025.100867","url":null,"abstract":"<div><div>Bismuth selenide (Bi<sub>2</sub>Se<sub>3</sub>) is a prototypical topological insulator that exhibits robust surface states with spin-momentum locking and high carrier mobility, making it a key material for quantum and spintronic applications. We systematically investigated the thickness-dependent morphological evolution and quantum transport properties of Bi<sub>2</sub>Se<sub>3</sub> thin films grown by a two-step thermal evaporation method. Films with thicknesses of 3–80 quintuple layers (QL) were deposited under high vacuum and annealed at 200 °C. Ultrathin films (≤ 9 QL) exhibited island-like discontinuous morphology and high resistance, while thicker films (> 9 QL) formed continuous, c-axis-oriented crystalline layers with enhanced smoothness and conductivity. The highest Raman peak intensity was obtained for the 9-QL film due to enhanced electron-phonon coupling, suggesting that 9 QL is the critical thickness for coherent phonon and carrier behavior. Magnetotransport measurements revealed weak antilocalization at low fields and an increasing contribution from bulk transport channels at high fields in thicker films. These findings provide insights into the nucleation-to-coalescence transition of layered Bi<sub>2</sub>Se<sub>3</sub> films and establish 9–40 QL as the optimal thickness range for accessing topological surface transport in quantum devices.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100867"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-01Epub Date: 2025-10-16DOI: 10.1016/j.apsadv.2025.100875
Jan Komeda, Antonio Cammarata, Tomas Polcar
Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive and selective technique. It greatly enhances the signal of an analyte compared to classical Raman spectroscopy, due to analyte–substrate interactions. A promising substrate for SERS is boron-doped graphene (B-graphene). At low boron concentrations of 1.39 at.%, it has been shown to enhance the Raman signal of simple organic molecules such as pyridine. The potential use of high-concentration B-graphene materials for SERS remains unexplored. Therefore, in our study, we investigate the influence of dopant concentration and relative adsorbate/substrate geometry on the effectiveness of B-graphene as a SERS substrate, with glucose as the analyte. We perform Density Functional Theory simulations using the PBE functional and the DFT-D2 van der Waals correction. By combining analysis of interatomic force constants and phonon eigenvector composition, we conclude that higher doping concentrations provide a larger enhancement to the Raman signal of glucose, while the molecule’s orientation relative to the surface plays a fundamental role in the Raman response. We suggest that 12.5 at.% B-graphene represents a potential substrate for SERS-based detection of glucose. Additionally, the phonon-based analysis can be promptly applied in the search for promising substrate materials for enhanced Raman response.
{"title":"Suitable boron-doped graphene substrate for glucose Raman signal enhancement","authors":"Jan Komeda, Antonio Cammarata, Tomas Polcar","doi":"10.1016/j.apsadv.2025.100875","DOIUrl":"10.1016/j.apsadv.2025.100875","url":null,"abstract":"<div><div>Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive and selective technique. It greatly enhances the signal of an analyte compared to classical Raman spectroscopy, due to analyte–substrate interactions. A promising substrate for SERS is boron-doped graphene (B-graphene). At low boron concentrations of <span><math><mo>∼</mo></math></span>1.39 at.%, it has been shown to enhance the Raman signal of simple organic molecules such as pyridine. The potential use of high-concentration B-graphene materials for SERS remains unexplored. Therefore, in our study, we investigate the influence of dopant concentration and relative adsorbate/substrate geometry on the effectiveness of B-graphene as a SERS substrate, with glucose as the analyte. We perform Density Functional Theory simulations using the PBE functional and the DFT-D2 van der Waals correction. By combining analysis of interatomic force constants and phonon eigenvector composition, we conclude that higher doping concentrations provide a larger enhancement to the Raman signal of glucose, while the molecule’s orientation relative to the surface plays a fundamental role in the Raman response. We suggest that 12.5 at.% B-graphene represents a potential substrate for SERS-based detection of glucose. Additionally, the phonon-based analysis can be promptly applied in the search for promising substrate materials for enhanced Raman response.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"30 ","pages":"Article 100875"},"PeriodicalIF":8.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145333873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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