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Wear-resistant performance is a critical property of the surface coated functional fabric during the cyclical abrasion of wearing procedure. However, inorganic nano-materials cannot easily graft onto the hydrophobic fabric substrate with weak interface interaction resulting in the unsatisfactory washing and wearing performance. Herein, the wear-resistant conductive polyester fabric with polyurethane - silver - polyurethane (PU-Ag-PU) sandwich micro-structure decoration was successfully fabricated via a facile spray coating route of water soluble polyurethane (WPU) and the in-situ synthesis of silver nanoparticles (AgNPs). The obtained fabric exhibits excellent conductivity with surface resistance of 4.95 Ω/sq. which is far below than the case without sandwich micro-structure (1.32 × 104 Ω/sq) because of the rearrangement and quantum tunneling effect of AgNPs in the nanocomposite coating layer. More importantly, the wear resistance of the modified fabric has been greatly enhanced owing to the two-phase structure of polyurethane and sandwich micro-structure of coating. The weight loss of the sandwich micro-structure coated fabric is only 1.28% while it is 5.58% of the case without PU outer coating layer. Meanwhile, surface resistance of the sandwich fabric is merely increased an order of magnitude even after 1500 times of abrasion cycle test, showing a qualitative enhancement compared with that of the common structure (increased seven orders of magnitude). In short, the designed sandwich micro-structure significantly enhanced the electrical conductivity and wear-resistance of silver decorated fabric. The strategy of sandwich micro-structure design in this paper has indicated a potential way for the durable wear-resistant functional fabrics.

High-performance fabrics with excellent electrical conductivity are increasingly attractive in modern industries. In this study, we report an electrically conductive silver/polyimide fabric (Ag/PIF) composite fabricated by combining an O 2 plasma pretreatment and a spray-assisted electroless plating (SAELP) technique. O 2 plasma treatment is firstly employed to roughen the surface of PIF and introduce functional aldehyde or ketone groups, which can act as a reducing agent and facilitate an even nucleation initiation of silver nanoparticles (Ag NPs) on the surface of the PIF. A silver ion solution and a reducing agent are then mixed evenly and sprayed to the PIF immediately to obtain Ag/PIF composites. The effects of O 2 plasma treatment and SAELP duration on the Ag/PIF composites are investigated and discussed. The results demonstrate that the silver layer is coated on the PIF uniformly and densely with a surface resistance of 0.1 Ω/sq. The first decomposition temperature of the Ag/PIF composites is up to 600 °C, indicating excellent thermal stability. The enhanced adhesion between Ag NPs and PIF endows the composites excellent fastness and superior flexibility. This work gives a new strategy for fabricating flexible, electrically conductive functional metal coated fabrics with high-performance properties in an efficient, facile and scalable way.

We have deposited a large area (10 × 10 cm2) Sb-doped SnO2 (ATO) thin film transparent conducting electrode (TCE) using chemical spray pyrolysis method. The XRD analysis confirms tetragonal crystal structure of ATO thin film with significant preferred orientation. The XPS analysis clearly indicates the presence of Sb in +5 charge state when substituted into the SnO2 lattice. The UV–Vis transmittance spectra of the film showed average transmittance of 77.5% at 550 nm and the calculated direct band gap value was 3.82 eV. As-deposited ATO film exhibited lowest sheet resistivity and resistance of 6.715 × 10−4 Ω cm and 31.91 Ω/□ respectively due to Sb-dopant effect into the Sn lattice. Doping with Sb into SnO2 exhibits high carrier concentration of 7.899 × 1020 cm−3 and mobility of 28.45 cm2/Vs resulting in enhanced electrical transport properties. The variation of the sheet resistance of the large area deposited film is estimated across every 1 × 1 cm2 surface area. Variation of sheet resistance of the ATO film as a function of annealing temperature and duration was found to be appreciably stable. Kelvin probe study yielded a surface work function of 5.14 eV for the ATO film indicating the suitability to serve as an indium-free alternate TCE for optoelectronic device applications.

As a highly conductive and transparent electrode, ITO/Ag/ITO multilayers are fabricated using an in-line sputtering method. Optimal thickness conditions have been investigated in terms of optical transmittance and electrical conductance. Considering the optical properties, the experimental characteristics are analyzed based on theoretical phenomena and compared with the simulated results. The simulations are based on the finite-difference-time-domain (FDTD) method in solving linear Maxwell equations. The results showed that ITO/Ag/ITO structures with respective thicknesses of 39.2 nm/10.7 nm/39.2 nm are most suitable with an average transmittance of 87% calculated for wavelengths ranging from 400 to 800 nm and a sheet resistance of about 7.1 Ω∕□. However, even with the optimum thickness conditions of the ‘ITO/Ag/ITO’ multilayers, the transmittances on some ranges of the visible wavelength were much lower than those of a single ITO layer. In order to improve the transmittance, Ag layer was formed with mesh structure. The transmittance and the sheet resistance in the ITO/Mesh-Ag/ITO multilayer structure were analyzed depending on the open ratio. As a result, a trade off in the open ratio was necessary in order to obtain the transmittance as high as possible and the sheet resistance as possible low. By the experiments, we found out that the transmittance was nearly same as the single ITO layer and the sheet resistance was about 30 Ω∕□ when the open ratio was about 85%.

The electrical transport of ultrathin films is an issue for modern electronics, since conduction properties of commonly used metals present important differences for thicknesses in the nanometer scale. This report shows that the sheet resistance of gold ultrathin films (between 1.2 nm and 3.8 nm) decreases up to 5 orders of magnitude when a chromium layer 0.8 nm thick is used as surfactant. The chromium layer changes the morphology of the gold films on mica, composed by large isolated grains, allowing the formation of a population of small grains between the large ones, therefore reducing the thickness at which the electrical percolation is achieved. The electrical percolation thickness, evidenced as a sharp decay in sheet resistance, occurs at 3.9 nm, for gold deposited directly on mica, while this value is reduced to 1.2 nm if a thin chromium layer is previously grown on the mica substrate. A deeper study of the electrical properties of this gold ultrathin films grown on Cr/mica show that above 2.8 nm, they already present a metallic behavior; while films near 2.2 nm show a zero temperature coefficient, meaning that the electrical conduction driven by tunneling still plays an important role in the electronic transport. Finally, is demonstrated, that the contribution of the chromium layer to the electrical conductivity of films can be neglected. Namely the influence of the chromium layer on metallic ultrathin films, is mainly as a surfactant, with no direct role in the electronic transport itself.

Interconnection of solar cells by an electrically conductive adhesive (ECA) can replace the use of conventional metal ribbon connections for photovoltaic module fabrication. This technology increases the active area for photocurrent generation because the cells are connected in a busbar-less structure, and high-power, high-efficiency modules can be manufactured. In this study, we investigated the influence of the curing conditions on the characteristics of the ECA film and interconnected cell. In addition, this paper presents a new method for extracting the resistance contribution of the ECA to the interconnected cell. A low sheet resistance of 60 s, regardless of the curing temperature. In addition, the sheet resistance was 60 s was required for a similar efficiency improvement at lower temperatures. Notably, the characteristics of the interconnected cell simulated using the extracted ECA resistance values were similar to the measurement results.

Highly robust and smooth silver nanowire flexible transparent electrodes (AgNW FTEs) with UV-curable polymeric resin as an overcoating layer were fabricated via successive Mayer rod method followed by UV light curing process, and the mechanical and chemical stabilities, electromagnetic interference shielding effectiveness (EMI SE) and film-heating property of the resultant overcoated AgNW FTEs were investigated. The results show that the fabricated AgNW FTEs with overcoating layer has a smooth surface with a root-mean-square (RMS) surface roughness value of 1.07 nm, and the overcoating layer generates a slight decrease of sheet resistance of AgNW FTEs from 8.1 to 7.9 Ω/sq, and the transmittance of 91.3% at 550 nm maintains basically. The overcoated AgNW FTE shows high mechanical and chemical stabilities, and the opto-electrical properties do not spoil after 10 times of scratching or 30 times of wiping or dipping into Na2S solution for 600 s. The overcoated AgNW FTEs possesses an EMI SE of 28.1 dB, and a heating temperature of 93.5 °C in 30 s on 12 V even after inputting and turning off the voltage for 30 times with a duration of 4 h. It indicates that the overcoated AgNW FTEs has great potential application in the fields of EMI shielding and film heater.

Controllable protein adsorption on solids is of great importance in many modern technological applications. The role of the water phase in mediating the protein-surface interactions, however, still remains poorly understood. Herein, we employ free energy calculations to systematically explore the mechanisms of the surface adsorption/bioresistance correlating with the interfacial water layers. The studied peptide shows strong binding affinity with the hydrophobic surface, as illustrated by a monotonic decrease in the free energy profile with no energy barriers. However, the surface bioresistance could be triggered in two distinct ways, by not only an enhancement of the surface-water interactions, but also increased interactions between the water and adsorbates. The enhanced surface-water interactions decrease the tendency of the surface dehydration and the subsequent adsorbate penetration into the surface-bound water layers, thus leading to the surface bioresistance. On the other hand, the enhanced water-adsorbate interactions could promote water stabilization of the adsorbate in the bulk solution, effectively preventing the peptide adsorption. Our results further elucidate that the increase in the peptide size favors its adsorption on the hydrophobic surface, but go against the adsorption on the hydrophilic surface. The mechanisms revealed here may facilitate the design of novel proteins/peptides, materials, and solvents for a controllable adsorption at a solid-water interface.

One of the key strategies for developing modern transparent optoelectronic devices is to achieve more conductive, transparent, and thermally-stable electrodes at minimal costs. Herein, we report a simple and cost-effective coaxial electrospinning process that produces continuous and ultra-long copper nanofibers (CuNFs) conformally covered with a shell layer of carbon black (CB). The electrospinning of Cu nanoparticles and CB inks enabled the fabrication of Cu (core)/CB (shell) nanofibers as network forms that were dispersed directly on target substrates with no additional deposition or lithography process. By virtue of the presence of the CB shell, the reflection of light from the metal surface, a critical limitation in existing metallic transparent conductive electrodes (TCEs), was reduced dramatically. Its reflection of light was even lower than that of bare quartz due to the suppressed backscattering of individual CuNFs, and this provided a high-clarity view through the black CuNF-TCEs while maintaining the high transparency of 91% and the low sheet resistance of 0.8 Ω/sq. Current-voltage experiments on single NF showed that a CuNF sustained a breakdown current density of 5 × 106 A/cm2, outperforming its counterpart silver NF and indicating the robustness of black CuNF-TCEs against electromigration. Such haze-free, thermally-stable black CuNF-TCEs enabled the demonstration of transparent heaters capable of working at extremely high temperatures; the maximum working temperature of the heaters was up to 800 °C, and the temperature was maintained for >90 min under an alternating current bias. We believe that the coaxial electrospinning of metal inks with other products will enable a variety of multi-functional metal NFs, leading to the development of next-generation displays, touch panels, and smart windows.

This work presents a broad study of transparent and conducting Al-doped ZnO (AZO) thin films that could replace indium tin oxide (ITO) as transparent electrode in optoelectronic devices. AZO thin films are deposited by pulsed DC magnetron sputtering at a sputtering power of 80 W with different pulse frequencies in the range 50–100 kHz. Diffraction data confirm formation of doped ZnO and AZO thin films exhibit preferred orientation in the c-direction. The crystallite sizes of Al:ZnO are in the range 16–21 nm. The field emission scanning electron microscopy and atomic force microscopy of AZO thin films reveal nucleation and growth of uniform and dense films with better quality films deposited at a pulse frequency 75 kHz. A simple and non-destructive optical method is adopted to determine thickness and dispersion parameters such as dispersion energy, carrier concentration to effective mass ratio, and plasma frequency. AZO thin films offer excellent visible light transparency and limited transparency in the near-infrared region due to free carrier absorption. The sheet resistance of AZO thin films is recorded in the range 9–45 Ω/sq making these transparent conducting oxides (TCOs) suitable for optoelectronic applications. The figure of merit as high as 1.99 × 10−2 Ω−1 is achieved for AZO thin film deposited at a pulse frequency of 75 kHz. AZO thin film sputtered with a pulse frequency of 75 kHz is quite stable in ambient oxidizing environment and surface adsorption sites might govern the initial oxidation of films when exposed to atmosphere. Excellent figure of merit and good stability of sputtered AZO thin films as TCO fulfill the requirements of a transparent electrode in photovoltaics.

Networks of silver nanowires (Ag-NWs) can be electrically conductive and optically transparent at the same time. Thus, Ag-NWs are promising candidates for substituting transparent and conductive oxides like indium-tin-oxide. Direct-write methods for printing patterns are suitable in order to reduce the amount of material used with respect to actual deposition methods on large areas that require post-processing steps. In this work, we study the laser-induced forward transfer of Ag-NWs with the aim of printing conductive patterns that appear invisible at naked eye. A Nd:YAG laser system delivering 150 ns pulses at 1064 nm wavelength was coupled with a scan head for printing the Ag-NWs at different pulse energies (0.20–0.45 mJ). It has been found that the area coverage of Ag-NWs, which is directly related with the optical an electrical properties of the patterns, increases as the laser pulse energy increases. A sheet resistance of 140 Ω/sq. is reached when printing at the highest pulse energy tested. As a proof-of-concept, we printed simple circuits with a pair of invisible electrodes connecting an LED on glass with a transmittance of 98.8%, a haze of 0.5%, a reflectance below 0.1% and a sheet resistance of 340 Ω/sq.

Due to its unique electrical and optical properties, copper (II) oxide (CuO) potentially has a wide variety of applications. It is commonly known that CuO has p-type conductivity; however, we report observations of n-type conductivity in thin CuO films by metal doping for the first time. We achieved n-type electrical conductivity in CuO films with cobalt (Co) doping. Undoped and Co-doped CuO thin films were fabricated using a spin coating technique. Electrical parameters, specifically, the charge carrier concentration, sheet resistance, and conductivity type were investigated using a van der Pauw Hall measurement system. By 3 per cent of the cobalt doping conductivity type conversion was observed. The effects of metal doping on the width of the optical band gap were investigated using ultraviolet-visible spectrometry over the wavelength range of 300–1100 nm. The optical band gaps were found to be 1.43, 1.44, 1.44, 1.42 eV for un-doped, 2, 4 and 6% Co doped CuO thin films, respectively. The influence of different concentration ratio on the growth of CuO films was investigated using XRD. Microstrain (e), crystalline size (D) and dislocation density (δ) for all orientations were calculated from XRD analysis.

In this work, transparent conductive oxide (TCO) film structures were designed with thin gallium (Ga) interlayers added in between zinc oxide (ZnO) and aluminium (1-at% Al)-doped zinc oxide (AZO)-based multilayers. The ZnO/Ga/ZnO and AZO/Ga/AZO films were grown on glass substrates and annealed in ambient argon (Ar). The lowest sheet resistance of 131.71 Ω / □ was obtained from the AZO/Ga/AZO films with 10 mg of Ga interlayer after annealing at 400 °C for 90 min in Ar. The average transmittance was approximately 80% in the visible region. The XRD showed a change of lattice parameters. It suggested that Ga3+ ions partially diffused into AZO-based layers similar to doping. The XPS survey spectra and the XPS depth profile showed the Ga2p3/2 peak at the position of metallic Ga and the diffusion of Ga atoms into the grain boundary of AZO. This means the annealed Ga in the middle layer moves via the lattice sites or between the lattice sites forming both substitution and interstices. These imply that the architected AZO/Ga/AZO multilayer system leads to increase of charge mobility as well as of carrier concentration.

Pure Cu film strongly adherent to glass substrates was deposited by printing Cu(COOH)2-containing paste and decomposing it at 250 °C in nitrogen atmosphere. The complete transformation of Cu(COOH)2 into Cu required 30 min and generated a low sheet resistance of 0.167 Ω/sq (volume resistivity: 15.0 μΩ·cm). Maximum adhesion between the Cu film and substrate was attained at the Cu complexes:α-terpineol mixing ratio of 6:4 by weight. The spike-shaped microstructure at the Cu/glass interface was determined to be the main cause for the outstanding adhesion properties. The resistance further decreased to 0.084 Ω/sq by increasing the thickness and modifying the surface of the Cu film via electroless Cu plating.

Silver nanowire (AgNW)/polymer composite films fabricated by roll-to-roll slot die-coating exhibit optical and electrical anisotropy. To evaluate the dependence of the film’s optical and electrical properties on the AgNW orientation, we quantify their polarized optical extinction and sheet resistance. Applying image analysis tools to microscope images, we show structural anisotropy due to a slightly preferential AgNW orientation. Optical anisotropy due to longitudinal- and transverse-mode surface plasmons resonances is predominantly observed in the lengthwise and crosswise direction of the composite films, respectively. Electrical anisotropy also depends on the measurement direction: sheet resistance is small in the lengthwise direction. These data indicate that the distribution of AgNWs is not fully isotropic, with their long axis preferentially oriented along the lengthwise direction of the composite films. Furthermore, although optical and electrical anisotropies are of comparable magnitude, both are smaller than the structural anisotropy. Optical anisotropy is still observed even when the amount of AgNWs increases, indicating that their orientation remains relatively constant. Electrical anisotropy is also preserved, indicating that junction resistance prevails in such composite films. The relationship between polarized transmittance and sheet resistance at a given measurement angle is consistent with a figure-of-merit equation often used for randomly-oriented AgNWs.

Potential applications of graphene-based materials in nanoscale electronic devices depends heavily on the versatility of synthesis and modification methods. The significant trend of graphene materials production is based on laser-induced synthesis. In this work, we investigate the laser-induced formation of graphene layers in pinewood by utilising near-infrared picosecond (10 ps) and nanosecond (10 ns) pulses. Effect of laser irradiation dose and pulse duration time on the quality of graphene materials was comparatively evaluated. Raman measurements showed the formation of high-quality few-layer graphene structures with I(2D)/I(G) and I(D)/I(G) ratios of 1.10 and 0.69, respectively, at the nanosecond-laser irradiation dose of 662 J cm−2. The average in-plane crystallite size estimated from the Raman data was found to be 31 nm. Sheet resistance measurements showed a correlation with Raman data and revealed a significant decrease in electric resistance for the ns-laser prepared sample with the highest I(2D)/I(G) ratio. To get insight into the graphene formation mechanism, we performed modelling of the pinewood surface temperature after the laser pulse irradiation. Higher surface temperatures reached and ablation process during picosecond laser irradiation disturb crystalline lattice structure forming lower-quality graphene platelets. We found that the nanosecond laser produces less defected graphene layers.

AgMgAl films with a thickness of 6–12 nm were deposited on glass substrates using a co-sputtering process. AZO layers were then deposited on the AMA films to form bi-layer structures. The films were processed by traditional furnace annealing at temperatures of 100–200 °C and laser annealing with a laser power of 25–800 mW and repetition rates ranging from 100 to 400 kHz. For the non-annealed samples, the sheet resistance reduced and the transmittance increased with the addition of the AZO film to the AMA layer. For the optimal AMA thickness of 12 nm, the sheet resistance was equal to 85 Ω/□, while the transmittance was equal to 74%. According to the DSC results, the crystallization temperature of the AMA film was around 100–150 °C. Following furnace annealing, the optoelectrical properties of the bi-layer structure improved due to the crystallization of the AMA film. Furthermore, for the laser-annealed film processed using a pulse energy of 0.5 μJ and a repetition rate of 400 kHz, the sheet resistance was reduced to 45 Ω/□, while the transmittance was improved to 87%.

It is crucial to enhance anti-oxidation resistance of copper nanowires (Cu NWs) without degrading their transparent conductive characteristics. Here, reduced graphene oxide/copper nanowires (RGO/Cu NWs) with coating nanostructures were synthesized by a facile one-pot hydrothermal method. The copper nanowire was prepared by using copper (I) chloride as the precursor while the graphene oxide (GO) was reduced using the polyols as the reducing agent in order to obtain the coating structure, abandoning conventional tedious multi-step preparation processes. The microstructure and morphology of RGO/Cu NWs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), selected-area electronic diffraction (SEAD) and X-ray photoelectron spectroscopy (XPS). The as-synthesized RGO/Cu NWs nanostructure is found to be almost coating structure of particle-free, high aspect ratio (L/D≈890) Cu NWs decorated with reduced graphene oxide (RGO), which accounts for the outstanding oxidation resistance. The stability tests show that the sheet resistance (RS) of the RGO/Cu NWs is almost unchanged over 20 days at room temperature or 5 h at 60 °C. What’s more, the sheet resistance of the RGO/Cu NWs with coating structure only increases to 2.48 times after being heated for 150 min at 100 °C, which can directly indicate that the RGO/Cu NWs nanostructure has excellent anti-oxidation resistance and temporal stability. Also, the as-prepared RGO/Cu NWs transparent electrode has both low sheet resistance of 58.36 Ω/sq and high optical transmittance (87.12% @550 nm). The composite materials provide a better strategy to resolve the problem of being easily oxidized for Cu NWs and promote their wide practical applications.

Large-area monolayer graphene by chemical vapor deposition as electrode in electronic devices always suffers from shortages of low conductivity and high contact resistance. In this work, we demonstrate a composite electrode by depositing a continuous and homogeneous ultrathin 7-nm Au film on monolayer graphene with low average sheet resistance of 24.6 Ω/□ and high transmittance of 74.6% at 520 nm. The excellent properties of the composite electrode are attributed to the suppressed Au Volmer-Weber growth mode of the ultrathin Au film by the organized hexagonal carbon lattices of graphene. Rigid supercapacitor based on the composite electrode exhibits a capacitance of 81.5 μF/cm2 at the scan rate of 0.1 V/s, which is 17 times higher than the device based on monolayer graphene. Flexible supercapacitor based on the composite electrode can be bending at curvature radius of 2 mm and with slight performance decrease over 1800 bending cycles.

We fabricate ion-gated field-effect transistors (iFET) on mechanically exfoliated multilayer MoS$_2$. We encapsulate the flake by Al$_2$O$_3$, leaving the device channel exposed at the edges only. A stable Li$^+$ intercalation in the MoS$_2$ lattice is induced by gating the samples with a Li-based polymeric electrolyte above $\sim$ 330 K and the doping state is fixed by quenching the device to $\sim$ 300 K. This intercalation process induces the emergence of anomalies in the temperature dependence of the sheet resistance and its first derivative, which are typically associated with structural/electronic/magnetic phase transitions. We suggest that these anomalies in the resistivity of MoS$_2$ can be naturally interpreted as the signature of a transition to a charge-density-wave phase induced by lithiation, in accordance with recent theoretical calculations., Comment: 8 pages, 4 figures

AZO/Cu/AZO films were prepared on glass substrates by direct-current magnetron sputtering at room temperature. The effects of the AZO layer on the infrared emissivity and photoelectric properties of AZO/Cu/AZO films were studied. The results show that the infrared emissivity and sheet resistance of the AZO/Cu/AZO films decrease with the AZO layer thickness, and then increase when further increasing the thickness to 40 nm. Meanwhile, the visible transmittance first increase and then decrease slightly. The multilayer film with 40 nm-thickness AZO layer shows the lowest sheet resistance of 9.96 Ω/sq, lowest infrared emissivity of 0.055 and high transmittance of 87.7 %. The sheet resistance and infrared emissivity are associated with the quality of top AZO layer and Cu layer. The bottom AZO layer with optimized thickness is beneficial to the growth of middle Cu layer and top AZO layer, which is facilitate to improve the performance of multilayer films.

The operation of the modern accelerators has long been challenged with the problems associated with distributed vacuum profile and electron multipacting. Applying a Ti-Zr-V based non-evaporable getter (NEG) film provides an ideal solution to these problems, except that TiZrV thin film may deteriorate the wakefield effect because of the increased wall resistivity. To deal with the trade-offs between those effects, an innovative quaternary TiZrVCu NEG film was prepared using magnetron sputtering technique in the present study. Through comparative study on the activation behavior, secondary electron yields and the surface resistivity of the novel TiZrVCu getter film with that of the conventional TiZrV film, it is found that alloying Cu into the TiZrV film would encouragingly eliminate the secondary electron yield and the d.c. resistivity of the NEG films, with a minor deterioration on the activation kinetics. The present study provides insights for optimizing the composition of NEG films from the aspect of realizing synergy manipulation of the activation kinetics, SEY and d.c resistivity.

The rapidly growing demand in wearable electronics has led to the development of transparent flexible conductive electrodes (TFEs) that feature excellent optoelectronic properties. Herein, a facile, eco-friendly and cost-effective strategy of electrospray assisted etching (ESAE) process is presented to fabricate honeycomb-like porous Ag nanowires (NWs) networks. A water-soluble silk fibroin (SF) film served as the mask layer to pattern the Ag NWs networks, on which quasi-periodical distributed holes were simply and spontaneously achieved by electrospraying water droplets to dissolve the SF film. The scale features of the dissolved holes could be adjusted by varying the electrospray parameters, leading to tailored Ag NW networks and customizable figure of merit (FOM). It was found that the quasi-periodic deposition of droplets was assisted by electric field forces. Compared with the fully-coated networks, the optimized porous networks had a well-controlled roughness, improved transmittance of 92.5%, well-maintained conductivity (29 Ω/sq) and excellent mechanical stability, resulting in 9.3% increase in FOM, and could be further customized according to the practical photoelectric demand. The conductivity dropped by only 4.9% after 10,000 bending cycles at a bending radius of 5 mm, demonstrating the good mechanical stability of the honeycomb structures. The simple and nontoxic ESAE process offers an ideal strategy for realizing the trade-off between transmittance and sheet resistance for different optoelectronic applications. Moreover, this strategy has universal scope and would be feasible for large area manufacturing.

Silver nanowires (AgNWs) show great potential in the fabrication of high-flexible transparent conductive films (TCFs) and reduced graphene oxide (rGO) has been considered as one of the most promising overcoating materials for improving the long-term stability of AgNW TCFs. However, transmittance, conductivity, and flexibility of AgNW TCFs are often compromised during the assembly of rGO film. Herein, a highly efficient process of preparing a high-performance and highly stable AgNW TCF is proposed. Firstly, a water-based, self-assembled coating method is used to achieve GO/AgNW TCFs. Then, the light absorption property of AgNWs is utilized to assist the reduction of the graphene oxide (GO) layer through the use of a microsecond intense pulsed light (IPL) irradiation treatment, resulting in a high-performance rGO/AgNW TCF. The instantaneous high-temperature rising from AgNWs provides additional and abundant thermal energy during the irradiation to reduce the ultra-thin GO film without damage to the nanostructure of the GO layer or to the AgNW TCFs itself. The achieved rGO/AgNW TCFs have a low sheet resistance to 8 Ω/sq and a high transmittance of 86.2% owing to the in-situ reduction of rGO film from thin GO film and welding between the AgNWs. In addition, this technique presents a robust enhancement of AgNW TCFs, not only with regard to their electrical stability in high-temperature and high-humidity atmospheres but also to their overall mechanical stability, which significantly enhances the application prospects of AgNW TCFs for use in flexible optoelectronic devices.

Transparent conductive CuS film was prepared on A4 sized polyethylene terephthalate (PET) substrate through chemical bath deposition method reacting at a mild temperature of 35 °C by using copper nitrate and thiourea as precursors and triethanolamine as complexing agent. Characterization studies showed that the as prepared nanoparticles were closely packed and tightly adhered onto the surface of the PET substrate with the highest ASTM 5B level, and formed a homogeneous nanosized CuS film with satisfied conductivity and transmittance. It was found that the light transmittance with the film was negatively correlated with its conductivity. When the light transmittance for the film prepared under optimized conditions was enhanced from 55.0 to 71.7%, the conductivity underwent a consistent deterioration, and the corresponding sheet resistance value was increased from 74.12 to 196.20 Ω/□. Although bending operation was testified to be an important influencing factor on the properties of the film and could let its resistance vary along with the decrease of curvature radius, the amplitude of variation was limited. Both of conductivity and transmittance remained almost unchanged for the film to which hundreds of severe bending operations were subjected.

A transparent conductive electrode (TCE) using the mxiture of graphite and silver nanowires (AgNWs) powder was fabricated with a nanoparticle deposition system (NPDS), a facile dry deposition approach using a graphite-AgNW powder mixture. The deposited film formed a composite structure with few-layered graphene, single layered graphene sheets, and AgNWs forming a fused junction under optimal heat treatment at 80 °C. The sheet resistance of the deposited film was measured to be 24–28 Ω/□, in accordance with values measured for commercial TCEs. Transmittance of 58–67% was measured for the deposited sample, which was lower than the 20–30% measured for conventional TCEs, due to scattering of incident light by few-layered graphene and AgNWs within the deposited film. An electrochromic (EC) cell with fabricated TCE performed well, showing a transmittance change of 15% at its wavelength of 630 nm. CV measurements were conducted for 500 cycles to confirm the stability of the EC device and TCE, and no performance degradation was observed for the device after 500 cycles, which represents good cyclic stability. Therefore, a TCE using graphite and AgNWs was successfully fabricated using the facile NPDS process, which represents a new fabrication process for TCEs based on graphene and AgNWs.

Aligned Nano rods of transparent conducting indium tin oxide (ITO) were deposited on glass substrates using dc magnetron sputtering technique from an ITO alloy target at two different oxygen pressures placing the substrates at three different lateral positions inside the chamber. The (4 4 0) oriented ITO thin films at optimal deposition conditions with high transmittance, low sheet resistance, good crystallinity and novel morphology was obtained at room temperature deposition. The structural, optical, morphological, electrical transport behavior and figure of merit imply the need in optimizing the positioning of the substrates within the chamber during deposition for achieving films of best desired properties.

This study presents the first use of a plasma reduction reaction under atmospheric pressure to fabricate a thin silver layer on polyethylene terephthalate (PET) film without the use of toxic chemicals, high voltages, or an expensive vacuum apparatus. The developed film is applied to electromagnetic interference (EMI) shielding. After repeatedly depositing a silver layer through a plasma reduction reaction on PET, we can successfully fabricate a uniformly deposited thin silver layer. It was found that both the particle size and film thickness of thin silver layers fabricated at different AgNO 3 concentrations increase with an increase in the concentration of AgNO 3 . However, the roughness of the thin silver layer decreases when increasing the concentration of AgNO 3 from 100 to 500 mM, and the roughness increases with a further increase in the concentration of AgNO 3 . The EMI shielding effectiveness (SE) of the film is measured in the frequency range of 0.045 to 1 GHz. As a result of optimizing the electrical conductivity by measuring sheet resistance of the thin silver layer, the film fabricated from 500 mM AgNO 3 exhibits the highest EMI SE among all fabricated films. The maximum values of the EMI SE are 60.490 dB at 0.1 GHz and 54.721 dB at 1.0 GHz with minimum sheet resistance of 0.244 Ω/□. Given that the proposed strategy is simple and effective, it is promising for fabricating various low-cost metal films with high EMI SE.

With the development of optoelectronic devices with three-dimensional (3D) structured surfaces, transparent electrodes that can be deposited on non-plane substrates have become increasingly important. In this paper, novel transparent silver nanowire (AgNWs)/ZnO film electrodes were uniformly prepared on treated 3D glass and PET substrates with a combination of spin-coating and heat-welding. The AgNWs/ZnO films show a transmittance of ∼88% and a sheet resistance of ∼10 Ω/sq. They are comparable with commercial ITO films. Furthermore, only a small in-plane resistance variation of ∼1 Ω/sq was measured using four-point probe mapping in films with a 10 cm × 10 cm area. These results confirm that these novel film electrodes are very uniform. Both electrical resistance and optical transmittance of the films remain mostly intact after 1000 bending cycles and tape peeling-tests with 10 cycles. The films show high thermal stability for more than one month at 80 °C. The strategy provides a new route for the design and fabrication of optoelectronic devices with 3D structured surfaces.

We report the use of triethylenetetramine (TETA) as a dopant of graphene transparent conducting electrodes (TCEs) for Si heterojunction solar cells. The molar concentration (nD) of TETA is varied from 0.05 to 0.3 mM to optimize the graphene TCEs. The TETA-doped graphene/Si Schottky solar cells show a maximum power-conversion efficiency (PCE) of 4.32% at nD = 0.2 mM, resulting from the enhanced electrical and optical properties, as proved from the nD-dependent behaviors of sheet resistance, transmittance, reflectance, series resistance, and external quantum efficiency. In addition, polymethylmethacrylate is employed as an antireflection layer to enhance the light-trapping effect on graphene/Si solar cells, resulting in further enhancement of the maximum PCE from 4.32 to 5.48%. The loss of the PCE is only within 2% of its original value during 10 days in air.

The dependence of the electrical and optical properties of radio frequency (RF) superimposed direct current (DC) sputtered–indium tin oxide (ITO) on the tin oxide (Sn2O3) content of the ITO is investigated, in order to elucidate an ohmic contact mechanism for the sputtered-ITO transparent electrodes on p-type gallium nitride (p-GaN). Contact resistivity of the RF superimposed DC sputtered-ITO on p-GaN in LEDs decreased when Sn2O3 content was increased from 3 wt% to 7 wt% because of the reduced sheet resistance of the sputtered-ITO with the increasing Sn2O3 content. Further increases in Sn2O3 content from 7 wt% to 15 wt% resulted in deterioration of the contact resistivity, which can be attributed to reduction of the work function of the ITO with increasing Sn2O3 content, followed by increasing Schottky barrier height at the sputtered ITO/p-GaN interface. Temperature-dependent contact resistivity of the sputtered-ITO on p-GaN also revealed that the ITO contacts with 7 wt% Sn2O3 yielded the lowest effective barrier height of 0.039 eV. Based on these results, we devised sputtered-ITO transparent p-electrodes having dual compositions of Sn2O3 content (7/10 wt%). The radiant intensity of LEDs having sputtered-ITO transparent p-electrodes with the dual compositions (7/10 wt%) was enhanced by 13% compared to LEDs having ITO with Sn2O3 content of 7 wt% only.

We investigate a fast and facile approach for the simultaneous synthesis and coating of conducting polyaniline (PANI) onto a substrate and the effects of processing conditions on the electrical properties of the fabricated films. Simultaneous polymerizing and depositing on the substrate forms a thin film with the average thickness of 300 nm and sheet resistance of 304 Ω/sq. Deposition conditions such as polymerization time (3–240 min), temperature (−10 to 40 °C), concentrations of monomer and oxidant (0.1–0.9 M), and type of washing solvents (acetone, water, and/or HCl solution) affect the film thickness, doping state, absorption characteristics, and solid-state nanoscale morphology, therefore affecting the electrical conductivity. Among the conditions, the surface-polymerized PANI film deposited at room temperature with acetone washing showed the highest conductivity of 22.2 S/cm.

It has been proved challenging to fabricate the single crystal orientation of VO 2 thin film by a simple method. Based on chemical reaction thermodynamic and crystallization analysis theory, combined with our experimental results, we find out that when stoichiometric number of metallic V in the chemical equation is the same, the ratio of metallic V thin film surface average roughness R a to thin film average particle diameter d decreases with the decreasing sputtering Argon pressure. Meanwhile, the oxidation reaction equilibrium constant K also decreases, which will lead to the increases of oxidation time, thereby the crystal orientation of the VO 2 thin film will also become more uniform. By sputtering oxidation coupling method, metallic V thin film is deposited on c-sapphire substrate at 1 × 10 −1 Pa, and then oxidized in the air with the maximum oxidation time of 65s, high oriented (020) VO 2 thin film has been fabricated successfully, which exhibits ∼4.6 orders sheet resistance change across the metal-insulator transition.

In this paper, the structural, surface, optical, and electrical properties of tungsten oxide thin films were analyzed. Eight sets of WOx thin films were prepared using the magnetron sputtering method. In each case, the sputtering process parameters were the same, except the Ar:O2 gas mixture ratios, which were intentionally changed from 1:1 to 10:1 to obtain various properties of the deposited thin film coatings. Structural properties analyzed with the aid of X-ray diffraction measurements results showed that all thin films were amorphous. X-ray photoelectron spectroscopy measurements revealed a shift of the binding energy for the W4f7/2 peak towards lower energies for increasing Ar:O2 ratio, indicating a possible change of stoichiometry and change of the oxygen vacancy concentration. It was also determined that the O/W atomic ratio at the surface of the thin films decreased from 3.01 to 2.55 with an increase of argon content in the magnetron sputtering atmosphere. Scanning electron microscope images revealed that all thin films had a smooth, homogenous, crack-free, and featureless, confirming the structural analysis. It was shown that the sputtering process atmosphere had a significant influence on the optical and electrical properties. Analysis of the transmittance spectra revealed that an increase of Ar:O2 ratio caused a gradual decrease of the average transparency in the visible wavelength range, an increase of the fundamental absorption edge, and decrease of the optical band gap energy. Moreover, the refractive index and extinction coefficient were analyzed, showing that the change of the argon content in the sputtering atmosphere significantly influenced on those parameters. The sheet resistance and resistivity of the prepared WOx thin films decreased with the increase of Ar:O2 ratio. The electrostatic charge dissipation times were measured for each coating to assess their antistatic properties. In turn, the hardness of tungsten oxide thin films increased with the increase of Ar:O2 ratio. It was found that thin films deposited with Ar:O2 ratio above 6:1 had good ability to dissipate static charge. Performed studies showed that a proper control of the gas atmosphere during magnetron sputtering of tungsten oxide thin films leads to tailoring their optoelectronic properties and creates an opportunity to design coatings destined for application in transparent electronics.

We present a facile and simple method for synthesizing a large-scale, well-dispersed, and high-concentration CuOx nanoparticle (NP) ink. CuOx thin films with ultrafine surfaces were fabricated using the synthesized NP ink by spin coating, which cannot be achieved using commercial NPs. The CuOx NP thin films were subjected to a subsequent laser digital patterning process, yielding finely-structured Cu electrodes on various polymer substrates with the minimum resistivity of 10.5 μΩ cm due to the laser-induced reductive sintering (LRS) phenomenon. Arbitrary Cu electrode patterns were directly generated on various flexible substrates under ambient conditions without any templating process. Cu-grid transparent conducting panels with a low sheet resistance (8.45 Ω sq−1) and high transmittance (87.4% at 550 nm) were prepared. Furthermore, the effect of the amount of polyvinylpyrrolidone, which was used as a dispersing and reducing agent in the NP ink, on the LRS phenomenon was analyzed in detail. Mechanical bending and twisting, cyclic bending, and tape pull tests confirmed the superior electromechanical stability of the Cu electrodes. The long-term oxidation resistance of the Cu electrodes under ambient conditions and the limiting temperature of oxidation resistance were also examined. Finally, a Cu-based flexible transparent touchscreen panel was demonstrated as a possible application.

Reduced graphene oxide coated soda lime glass can act as an alternative transparent/conducting electrode for many opto-electronic applications. However, bonding between the deposited reduced graphene oxide film and the glass substrate is important for achieving better stability of the coating and an extended device lifetime. In the present study, delamination energy of reduced graphene oxide on soda lime glass was quantified by using nanoscratch technique. Graphene oxide was deposited on soda lime glass by dip coating technique and was thermally reduced at different temperatures (100 °C, 200 °C, 300 °C, 400 °C and 500 °C) and treatment time (2 h, 3 h, 4 h, 5 h and 10 h) in Ar (95%) with H 2 (5%) atmosphere. An inverse behavior of delamination energy with temperature and treatment time was observed, which could be correlated with the removal of oxygen functional groups. Sheet resistance of the film demonstrated a steady decay with increasing temperature and treatment time. Functional groups attached to the graphene planes have more influence on conductivity than groups attached to the edges. Removal of functional groups could also be related to optical transmittance of the samples. Knowledge generated in this study with respect to delamination energy, sheet resistance and optical transmittance could be extensively used for various opto-electronic applications.

A transparent conductive electrode (TCE) based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was developed using a dry deposition method for application as an electrochromic (EC) device. To improve its electrical conductivity and stable EC performance, AgNW and TiO 2 nanoparticles were included in the TCE film. The resulting TiO 2 /AgNW/PEDOT:PSS hybrid film showed electrical sheet resistivity of 23 Ω/sq., similar to that of a commercial TCE film. When +2.0 V was applied to the hybrid film, the response current was stable, maintaining a value of 2.0 mA. We found that the hybrid film could be used as an EC device, without using commercial TCE film. Antimony-doped tin oxide on indium-doped tin oxide-glass as an ion-storage layer was combined with the hybrid film, with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI) injected into the EC device as an ionic liquid electrolyte. The optical transmittance difference between the colored and bleached states was 23% at 630 nm; under applied voltages of −2.0 V and +2.0 V, the coloration efficiency was 127.83 cm 2 /C. Moreover, cyclic transmittance with switching voltage for 3 h showed stable optical transmittance of 31% at 630 nm. Cyclic voltammetry measurements indicated stable behavior over 50 cycles. Thus, the proposed TCE configuration (TiO 2 /AgNW/PEDOT:PSS) shows great potential as a substitute for commercial TCEs, the cost of which depends on the availability of rare-earth materials.