Influence of Ag incorporation on the structural,optical and electrical properties of ITO/Ag/ITO multilayers for inorganic all-solid-state electrochromic devices

Indium tin oxide/silver/indium tin oxide (ITO/Ag/ITO, IAI) multilayer structures were prepared by DC magnetron sputtering as a conductive transparent electrode for inorganic all-solid-state electrochromic devices. A thin layer of silver (Ag) with various thicknesses was inserted between two layers of ITO films. The XRD and SEM results revealed that the microscopic morphology of Ag film was closely related to the thickness. Besides, the electrical and optical properties of the IAI multilayers were significantly influenced by the Ag layer thickness. The optimized IAI multilayers demonstrated the best combination of electrical and optical properties with a figure of merit of 54.05 (sheet resistance of 6.14 Ω/cm²and optical transmittance of 90.83%) when the Ag film was 10 nm thick. In order to evaluate the IAI multilayers as a transparent electrode for electrochromic applications, two ECDs with the structures of ITO/NiO_x/LiPON/WO₃/ITO and ITO/NiO_x/LiPON/WO₃/IAI were prepared, and their electro-optical properties were characterized by cyclic voltammetry (CV), chronoamperometry (CA) and spectroscopic measurements. Compared with ECD the pure ITO top electrode (ITO/NiO_x/LiPON/WO₃/ITO), the ECD with the IAI top electrode (ITO/NiO_x/LiPON/WO₃/IAI) presented a slightly smaller optical modulation amplitude, but a faster switching speed. All our findings indicate that the IAI multilayer structure is a promising alternative to the ITO thin film for inorganic all-solid state electrochromic applications.     

Efficiency improvement of CIGS solar cells using RF sputtered TCO/Ag/TCO thin-film as prospective buffer layer

In this paper, TCO (Transparent Conductive Oxide) incorporating ultrathin Ag intermediate film is proposed as a new buffer layer to enhance the efficiency of CIGS thin-film solar cells (TFSCs). In this regard, versatile multilayer thin-films based on ZnO/Ag/ZnO and ITO/Ag/ITO structures were deposited on glass using RF magnetron sputtering technique to determine the optoelectronic parameters of the multilayer structures. The elaborated samples were then characterized using SEM, EDS, XRD, and UV–Visible absorption spectroscopy techniques to investigate the structure morphological, optical, and electronic properties. The deposited multilayer thin-films showed amorphous-like structure and exhibited a broadband absorbance over the visible and even NIR spectrum ranges, indicating its potential application as alternative buffer layers for thin-film solar cells. In this context, TCO/Ag/TCO/CIGS solar cells have been numerically investigated using the deposited multilayer optoelectronic properties. It was revealed that the estimated efficiency of the ZnO/Ag/ZnO/CIGS-based solar cell could reach 18.5% with an open circuit voltage of 0.7 V and a short-circuit current density of 34.8 mA/cm². The performances exhibited by the investigated solar cell demonstrated that ZnO/Ag/ZnO multilayer can be used as an alternative to the conventional CdS buffer layer for developing high-performance non-toxic CIGS solar cells.     

Mechanical performance of ITO/Ag/ITO multilayer films deposited on glass substrate by RF and DC magnetron sputtering

ITO/Ag/ITO multilayer thin films have been a potential substitute of the conventional single-layer transparent conducting film. Nevertheless, the mechanical stability under preparation and in-service conditions still limits their applications and developments. In this paper, the influences of different structural properties as well as layer structure on both surface morphological properties and mechanical properties of the ITO/Ag/ITO multilayer thin films in comparison with commercial single-layer ITO thin film were systematically investigated. The results demonstrate that, i) the tri-layer composite has large impacts on the preferential orientation, and exhibits the decreased values of surface roughness, net lattice distortion and residual stress; ii) the increased hardness (H) and decreased Young's modulus (E) for full annealed ITO/Ag/ITO multilayer films indicate that it is possible to tailor mechanical properties of the materials by manufacturing multilayer composite; iii) the ITO/Ag/ITO multilayer thin film exhibits remarkable improvements in wear resistance with the increase of annealing temperature, which is mainly attributed to the increased ratios of H/E and H³/E².     

Conductive and transparent multilayer films for low-temperature TiO2/Ag/SiO2 electrodes by E-beam evaporation with IAD

Conductive and transparent multilayer thin films consisting of three alternating layers (TiO₂/Ag/SiO₂, TAS) have been fabricated for applications as transparent conducting oxides. Metal oxide and metal layers were prepared by electron-beam evaporation with ion-assisted deposition, and the optical and electrical properties of the resulting films as well as their energy bounding characteristics and microstructures were carefully investigated. The optical properties of the obtained TAS material were compared with those of well-known transparent metal oxide glasses such as ZnO/Ag/ZnO, TiO₂/Ag/TiO₂, ZnO/Cu/ZnO, and ZnO/Al/ZnO. The weathering resistance of the TAS film was improved by using a protective SiO₂ film as the uppermost layer. The transmittance spectra and sheet resistance of the material were carefully measured and analyzed as a function of the layer thickness. By properly adjusting the thickness of the metal and dielectric films, a low sheet resistance of 6.5 ohm/sq and a high average transmittance of over 89% in the 400 to 700 nm wavelength regions were achieved. We found that the Ag layer played a significant role in determining the optical and electrical properties of this film.     

Thermally stable and transparent F-doped SnO2 (FTO) /Ag/FTO films for transparent thin film heaters used in automobiles

We investigated the characteristics of F-doped SnO₂ (FTO)/Ag/FTO films prepared using thermal evaporation at room temperature for the application of the as-formed films in transparent thin film heaters (TFHs) of automobiles. To optimize the electrical and optical properties of the FTO/Ag/FTO multi-layer, the figure of merit (FoM) values of the FTO/Ag/FTO multi-layers were compared as a function of the thickness of the Ag and FTO layers. The sheet resistance and optical transmittance of the FTO/Ag/FTO multi-layer were primarily affected by the Ag inter-layer and bottom/top FTO thicknesses, respectively. At optimized Ag (10 nm) and FTO (40 nm) thicknesses, we fabricated a FTO/Ag/FTO electrode with a sheet resistance of 8.00 Ohm/square, an optical transmittance of 83.04 % at a visible wavelength (400–800 nm) and a FoM value of 19.49 Ohm^-1. The TFHs comprising the optimal FTO/Ag/FTO electrode exhibited a saturated temperature of 117 °C at a low operating direct current of 6 V, owing to the low sheet resistance. In addition, the FTO/Ag/FTO-based TFHs exhibited thermally stable performances owing to the stability of the bottom and top FTO electrodes. The performance of the FTO/Ag/FTO-based TFHs demonstrated that the thermally evaporated FTO/Ag/FTO multi-layer is a promising, stable, and transparent electrode material for application in the front window TFHs used in automobiles.     

Self-healing of TiSiN/Ag coatings induced by Ag

Ceramic coatings often suffer from the formation and expansion of microcracks, which leads to a failure of the protective function. In this work, we observed self-healing of the microcracks in the TiSiN/Ag multilayer coating upon heating. This behavior can be attributed to diffusion of the Ag atoms to the cracks in the multilayer coating, while similar cracks in the TiSiN monolayer coating remain unchanged after the same treatment. Furthermore, the TiSiN/Ag coating with healed cracks possesses similar electrochemical corrosion and biofouling properties to the as-deposited one, suggesting that TiSiN/Ag is a promising system in marine engineering applications. The mechanism of self-healing was explained by kinetic simulations based on ab initio molecular dynamics and the diffusion activation energies of Ag in irregular ceramic structures have been calculated. The here adopted theoretical method also provides a new pathway for exploring new coating systems with a potential self-healing function.     

ZnMgBeO/Ag/ZnMgBeO transparent multilayer films with UV energy bandgap and very low resistance

The ZnMgBeO/Ag/ZnMgBeO multilayer structures were sputter grown and their electrical and optical properties have been investigated in detail. Results indicated that the ZnMgBeO(30 nm)/Ag(10 nm)/ZnMgBeO(30 nm) optimum structure shows energy bandgap of ~4.5 eV, electrical resistivity of ~6.5×10⁻⁵ Ωcm, and optical transmittance of 78–90% over the visible wavelength range and 74–90% over 300–400 nm range, representing a significant improvement over the previously reported transparent conducting films. High resistivity (~0.12 MΩcm) of the ZnMgBeO layer did not critically affect the conductivity of the multilayer, because the Ag films act as the conducting path. It was also observed that the properties were substantially deteriorated at the Ag thickness of 5 nm, as the Ag film is only partly continuous, resulting in very rough interfaces and surfaces.     

Ag靶弧流对TiN/Ag多层膜结构和性能的影响

采用电弧离子镀技术,通过改变Ag电弧靶的弧流在医用不锈钢基底表面制备TiN/Ag多层膜,分析多层膜的微观结构,测试多层膜的厚度、结合强度和硬度,通过摩擦磨损实验测定多层膜的摩擦系数,研究了不同Ag靶弧流对多层膜结构和性能的影响规律。实验结果表明,在不同Ag靶弧流下,TiN/Ag多层膜有TiN(111)晶面和Ag(111)晶面择优生长。Ag靶弧流在一定程度上影响着多层膜中Ag的结晶度,当弧流为50 A时,Ag的结晶度达到最佳,此时多层膜的结合力最大,为45.33 N;多层膜的硬度达到最小值1 189.4 HV;多层膜的摩擦系数最小,为0.242。Ag靶弧流影响Ag层的结晶度,并且对多层膜的结合强度、硬度和摩擦系数具有明显影响。     

Preparation of ITO/Ag nanohybrid particles by a reverse micellar layer-by-layer coating

Silver (Ag) nanoparticles were adsorbed preferentially on indium tin oxide (ITO) surface to form composite particles using a reverse micellar layer-by-layer deposition. The micellar process stabilized the Ag particles by an anionic sodium bis(2-ethylhexyl) sulfosuccinate (AOT) surfactant in isooctane solvent. The ITO particles surface was mediated by a cationic poly(allylamine hydrochloride) (PAH) polyelectrolyte. The heterogeneous deposition was rendered by both electrostatic attraction and hydrophilic/hydrophobic interaction, and was carried out in multiple coating cycles. The resulting hybrid particles were characterized by zeta-potential measurement, electron microscopy, X-ray diffractometry, and inductively coupled plasma analysis, respectively. Optical transmittance of the ITO/Ag composite films was found to decrease substantially with the Ag deposition over the visible wavelengths range, arising mainly from scattering induced by the Ag nanoparticles.     

Flexible IZO/Ag/IZO/Ag multilayer electrode grown on a polyethylene terephthalate substrate using roll-to-roll sputtering

We investigated the optical, electrical, structural, and surface properties of roll-to-roll [R2R] sputter-grown flexible IZO/Ag/IZO/Ag [IAIA] multilayer films on polyethylene terephthalate substrates as a function of the top indium zinc oxide [IZO] thickness. It was found that the optical transmittance of the IAIA multilayer was significantly influenced by the top IZO layer thickness, which was grown on identical AIA multilayers. However, the sheet resistance of the IAIA multilayer was maintained between the range 5.01 to 5.1 Ω/square regardless of the top IZO thickness because the sheet resistance of the IAIA multilayer was mainly dependent on the thickness of the Ag layers. Notably, the optimized IAIA multilayer had a constant resistance change (ΔR/R ₀) under repeated outer bending tests with a radius of 10 mm. The mechanical integrity of the R2R-sputtered IAIA multilayer indicated that hybridization of an IZO and Ag metal layer is a promising flexible electrode scheme for the next-generation flexible optoelectronics.     

Control of refractive index by annealing to achieve high figure of merit for TiO2/Ag/TiO2 multilayer films

We modified the refractive index (n) of TiO₂ by annealing at various temperatures to obtain a high figure of merit (FOM) for TiO₂/Ag/TiO₂ (45 nm/17 nm/45 nm) multilayer films deposited on glass substrates. Unlike the as-deposited and 300 °C-annealed TiO₂ films, the 600 °C-annealed sample was crystallized in the anatase phase. The as-deposited TiO₂/Ag/as-deposited TiO₂ multilayer film exhibited a transmittance of 94.6% at 550 nm, whereas that of the as-deposited TiO₂/Ag/600 °C-annealed TiO₂ (lower) multilayer film was 96.6%. At 550 nm, n increased from 2.293 to 2.336 with increasing temperature. The carrier concentration, mobility, and sheet resistance varied with increasing annealing temperature. The samples exhibited smooth surfaces with a root-mean-square roughness of 0.37–1.09 nm. The 600 °C-annealed multilayer yielded the highest Haacke's FOM of 193.9×10⁻³ Ω⁻¹.     

复合纳米棒状Ag3PO4/ZnO材料的光催化性能

以一维棒状ZnO为载体,采用原位生长法制备纳米棒状Ag_3PO_4/ZnO复合材料。通过XRD、SEM、TEM、XPS和UV-Vis-DRS等测试对纳米棒状Ag_3PO_4/ZnO复合材料进行了表征,并评价了样品在可见光下的光催化性能。结果显示,ZnO几乎无可见光活性,通过水热法制备的ZnO形貌发生了改变,为比表面积的增加做出了贡献,为Ag_3PO_4提供了更多的负载可能。在可见光照射下,纯ZnO和Ag_3PO_4对苯酚的降解率分别为20%和38%,复合材料Ag_3PO_4/ZnO对苯酚的降解率为91.24%,光催化降解性能明显高于纯ZnO和Ag_3PO_4。最后,光催化稳定性的研究证明,Ag_3PO_4/ZnO复合材料形成了有效的异质结结构,抑制了电子-空穴的复合,提高了Ag_3PO_4/ZnO复合材料的稳定性。     

Multispectral photodetection using low-cost sputtered NiO/Ag/ITO heterostructure: From design concept to elaboration

High-performance multispectral photodetectors (PDs) are highly attractive for the emerging optoelectronic applications. In this work, a new broadband PD based on p-NiO/Ag/n-ITO heterostructure was fabricated by RF magnetron sputtering technique at room temperature. The tri-layered structure offering multispectral detection property was first identified using theoretical calculations based on combined FDTD and Particle Swarm Optimization (PSO) techniques. The crystal structure of the elaborated sensor was analyzed using X-ray diffraction (XRD) method. The device optical properties were investigated by UV–Vis–NIR spectroscopy. The NiO/Ag/ITO heterostructured PD shows a high average absorbance of 63% over a wide spectrum range of [200 nm–1100nm]. Compared with NiO and ITO thin-films, the performances of the heterostructured device are considerably enhanced. It was found that the prepared PD with NiO/Ag/ITO heterostructure merges the benefits of multispectral photodetection with reduced optical losses and efficient transfer of photo-induced carrier. The device demonstrated a high I_ON/I_OFF ratio of 78 dB and an enhanced responsivity under UV, visible and NIR lights (171 mA/W at 365 nm, 67 mA/W at 550 nm and 93 mA/W at 850 nm). The broadband photodetection property enabled by the optimized NiO/Ag/ITO heterostructure opens a new route for the elaboration of low-cost devices that can offer multiple sensing purposes, which are highly suitable for optoelectronic applications.     

[BN/CoPt]n/Ag薄膜的结构与磁性

采用磁控溅射方法在玻璃基片上制备了[BN/CoPt]n/Ag薄膜,并在600℃退火30min。结果表明,周期数（n）和Ag底层厚度（x）对CoPt薄膜结构和磁性有着重要的影响,周期数适当时（n=5）有利于易磁化轴（c轴）垂直于膜面取向,从而具有高的垂直磁各向异性;Ag底层可以诱导L10-CoPt相的形成并使c轴垂直择优取向,且Ag适量时（x=10nm）其诱导效应最强。     

Transparent SiON/Ag/SiON multilayer passivation grown on a flexible polyethersulfone substrate using a continuous roll-to-roll sputtering system

We have investigated the characteristics of a silicon oxynitride/silver/silicon oxynitride [SiON/Ag/SiON] multilayer passivation grown using a specially designed roll-to-roll [R2R] sputtering system on a flexible polyethersulfone substrate. Optical, structural, and surface properties of the R2R grown SiON/Ag/SiON multilayer were investigated as a function of the SiON thickness at a constant Ag thickness of 12 nm. The flexible SiON/Ag/SiON multilayer has a high optical transmittance of 87.7% at optimized conditions due to the antireflection and surface plasmon effects in the oxide-metal-oxide structure. The water vapor transmission rate of the SiON/Ag/SiON multilayer is 0.031 g/m² day at an optimized SiON thickness of 110 nm. This indicates that R2R grown SiON/Ag/SiON is a promising thin-film passivation for flexible organic light-emitting diodes and flexible organic photovoltaics due to its simple and low-temperature process.     

Essential Macleod Program (EMP) simulated fabrication of high quality Zn:SnO2/Ag/Zn:SnO2 multilayer transparent conducting electrode on flexible substrates

In the quest of promising Indium free amorphous transparent conducting oxide (TCO), Zn-doped SnO₂/Ag/Zn-doped SnO₂ (OMO) multilayer films were prepared on flexible polyethylene terephthalate (PET) substrates by RF sputtering at room temperature (RT). Growth parameters were optimized by varying sputtering power and working pressure, to have high electrical conductivity and optical transmittance. Optimization of the thickness of each layer was done by Essential Macleod Program (EMP) simulation to get the higher transmission through OMO multilayer. The sheet resistance and transmittance of 3 at% Zn-doped SnO₂ thin film (30 nm) were 2.23 kΩ/□, (ρ ~ 8.92×10⁻³ Ω∙cm) and 81.3% (at λ ~ 550 nm), respectively. By using optimized thicknesses of Zn-doped SnO₂ (30 nm) and Ag (12 nm) and optimized growth condition Zn-doped SnO₂/Ag/Zn-doped SnO₂ multilayer thin films were deposited. The low sheet resistance of 7.2 Ω/□ and high optical transmittance of 85.1% in the 550 nm wavelength region was achieved with 72 nm multilayer film.     

Silver nanoparticles synthesized from mesoporous Ag/SBA-15 composites

Silver nanoparticles were prepared by removing silica from mesoporous Ag/SBA-15 composites. The results of nitrogen adsorption–desorption isotherms, X-ray diffraction, transmission electron microscopy and UV–vis spectroscopy indicated that Ag nanoparticles existed in the pore channels of SBA-15. Ag nanoparticles with diameters in the range of 2.5–5.5 nm and a narrow size distribution were confirmed by atomic force microscope images and energy-dispersive X-ray spectroscopy. UV–vis spectroscopy showed a broad emission peak of Ag nanoparticles centered at ca. 438 nm.     

Fabrication of ZnO:Ag/GO composite thin films for enhanced photocatalytic activity

Zinc Oxide (ZnO), ZnO/GO (Graphene Oxide) and ZnO:Ag/GO nanocomposite thin films were deposited on glass substrates using a simple cost-effective automated jet nebulizer spray pyrolysis technique for photocatalytic degradation of organic dyes. The ZnO:Ag/GO film exhibits superior photocatalytic activity when compared with ZnO and ZnO/GO films. The degradation rate constant values of pristine ZnO and ZnO/GO films are found to be 0.0143 and 0.0176 min⁻¹, respectively whereas that of ZnO:Ag/GO is 0.0567 min⁻¹. The possible mechanism involved in the enhanced photocatalytic activity of ZnO:Ag/GO films for the degradation of Methylene Blue dye is proposed with the help of structural, optical and photoluminescence studies. The powder XRD profile confirms the hexagonal wurtzite structure of the synthesized catalysts. The results of Raman, XPS and EDX studies confirm the presence of GO in the ZnO/GO and GO and Ag in the ZnO:Ag/GO films.     

Fabrication of highly efficient TiO2/Ag/TiO2 multilayer transparent conducting electrode with N ion implantation for optoelectronic applications

Fabrication of highly conductive and transparent TiO₂/Ag/TiO₂ (referred hereafter as TAT) multilayer films with nitrogen implantation is reported. In the present work, TAT films were fabricated with a total thickness of 100 nm by sputtering on glass substrates at room temperature. The as-deposited films were implanted with 40 keV N ions for different fluences (1×10¹⁴, 5×10¹⁴, 1×10¹⁵, 5×10¹⁵ and 1×10¹⁶ ions/cm²). The objective of this study was to investigate the effect of N⁺ implantation on the optical and electrical properties of TAT multilayer films. X-ray diffraction of TAT films shows an amorphous TiO₂ film with a crystalline peak assigned to Ag (111) diffraction plane. The surface morphology studied by atomic force microscopy (AFM) and field emission scanning electron microscope (FESEM) revealed smooth and uniform top layer of the sandwich structure. The surface roughness of pristine film was 1.7 nm which increases to 2.34 nm on implantation for 1×10¹⁴ ions/cm² fluence. Beyond this fluence, the roughness decreases. The oxide/metal/oxide structure exhibits an average transmittance ~80% for pristine and ~70% for the implanted film at fluence of 1×10¹⁶ ions/cm² in the visible region. The electrical resistivity of the pristine sample was obtained as 2.04×10⁻⁴ Ω cm which is minimized to 9.62×10⁻⁵ Ω cm at highest fluence. Sheet resistance of TAT films decreased from 20.4 to 9.62 Ω/□ with an increase in fluence. Electrical and optical parameters such as carrier concentration, carrier mobility, absorption coefficient, band gap, refractive index and extinction coefficient have been calculated for the pristine and implanted films to assess the performance of films. The TAT multilayer film with fluence of 1×10¹⁶ ions/cm² showed maximum Haacke figure of merit (FOM) of 5.7×10⁻³ Ω⁻¹. X-ray photoelectron spectroscopy (XPS) analysis of N 1s and Ti 2p spectra revealed that substitutional implantation of nitrogen into the TiO₂ lattice added new electronic states just above the valence band which is responsible for the narrowing of band gap resulting in the enhancement in electrical conductivity. This study reports that fabrication of multilayer transparent conducting electrode with nitrogen implantation that exhibits superior electrical and optical properties and hence can be an alternative to indium tin oxide (ITO) for futuristic TCE applications in optoelectronic devices.     

Influence of Ag mid-layer in the optical and thermal properties of ZnO/Ag/ZnO thin films on the glass used in Buildings as insulating glass unit (IGU)

The low-emissivity (low-E) coatings are multiple ultra thin layers on glass used for producing spectrally selective glazing. The use of low-E glazing in building windows makes it possible limit the radiative heat transfer without reducing the visible transmittance perceptibly and accordingly alter the necessary natural lighting in low energy buildings. In this study, we investigate ZnO/Ag/ZnO thin films deposited on glass substrate via RF and DC sputtering by ZnO and Ag targets respectively, in various deposition time of Ag layer. We tried to diminish the NIR transmittance by using a feasible and affordable method with a low number of ultra thin layers and by reducing the cost of the vacuum.Presented results are related to electrical, optical and thermal properties for tri-layers based on sandwiched Ag by ZnO in deposition time of 10–45?s at room temperature.