Plasticized Polymer Interlayer for Low-Temperature Fabrication of a High-Quality Silver Nanowire-Based Flexible Transparent and Conductive Film

Mesh size control in forming an Ag/AgO nano-network structure for transparent conducting application

The variation behaviors of the morphology, transmission, and sheet resistance of the surface Ag/AgO nano-network (NNW) structures fabricated under different illumination conditions and with different Ag deposition thicknesses and thermal annealing temperatures in forming initial Ag nanoparticles (NPs) are studied. Generally, an NNW structure with a smaller mesh size or a denser branch distribution has a lower transmission and a lower sheet resistance level. Under the fabrication condition of a broader illumination spectrum, a lower thermal annealing temperature, or a thicker Ag deposition, we can obtain an NNW structure of a smaller mesh size. The mesh size of an NNW structure is basically controlled by the seed density of Brownian tree (BT) at the beginning of light illumination. A BT seed can be formed through a stronger local localized surface plasmon resonance for accelerating Ag oxidation in a certain region. Once an Ag/AgO BT seed is formed, the surrounding Ag NPs are reorganized to form the branches of a BT. Multiple BTs are connected to form a large-area NNW structure, which can serve as a transparent conductor. Under the fabrication conditions of a broader illumination spectrum, 3 nm Ag deposition, and 100 °C thermal annealing, we can implement an NNW structure to achieve ∼1.15μm in mesh size, ∼90 Ω sq^-1in sheet resistance, and 93%-77% in transmittance within the wavelength range between 370 and 700 nm.

All-Solution-Processed Molybdenum Oxide-Encapsulated Silver Nanowire Flexible Transparent Conductors with Improved Conductivity and Adhesion

A novel transparent conductive conductor composed of a silver nanowire (AgNW) network and MoO_x on a flexible polyethylene terephthalate (PET) substrate, with contemporaneously improved adhesion and reduced resistivity, is prepared using the full-solution process without high-temperature annealing. Under the optimized conditions, a MoO_x/AgNW/MoO_x multilayer is achieved, which shows much superior optoelectronic performance to that obtained from ITO with a high optical transmittance of 89.2% and a low sheet resistance of ∼12.5 Ω/sq. Unlike pure AgNW films, the sheet resistance is little changed after the tape and ultrasonication tests, illustrating a very strong adhesion to the PET substrate after the encapsulation of MoO_x. Moreover, the multilayer film exhibits excellent stability to resist mechanical bending and acid damage. In addition, the successful implementation of the flexible transparent heater demonstrates the practical application value of the electrode.

Optoelectronic and Electrothermal Properties of Transparent Conductive Silver Nanowires Films

Silver nanowires (AgNWs) show promise for fabricating flexible transparent conductors owing to their excellent conductivity, high transparency, and good mechanical properties. Here, we present the fabrication of transparent films composed of AgNWs with diameters of 20-30 nm and lengths of 25-30 μm on polyethylene terephthalate substrates and glass slides substrates using the Meyer rod method. We systematically investigated the films' optoelectronic and electrothermal properties. The morphology remained intact when heated at 25-150 °C and the AgNWs film showed high conductivity (17.6-14.3 Ω∙sq-1), excellent transmittance (93.9-91.8%) and low surface roughness values (11.2-14.7 nm). When used as a heater, the transparent AgNW conductive film showed rapid heating at low input voltages owing to a uniform heat distribution across the whole substrate surface. Additionally, the conductivity of the film decreased with increasing bending cycle numbers; however, the film still exhibited a good conductivity and heating performances after repeated bending.

Highly conductive and stretchable film fabricated by efficient transfer of silver nanowires

Wearable devices have become an important development direction for future consumer electronics, and films with conductivity, stretchability, and transparency are crucial for achieving wearability. In this article, silver nanowires (AgNWs) with a certain aspect ratio and Al2O3-polyethylene terephthalate films with specific size pit structures were prepared. Uniform coating of the AgNW layer and polydimethylsiloxane transfer were successfully realized. The surface resistance of the final obtained film was 14 Ω/sq with a light transmittance of 50.57%. During repeated deformations, the film conductivity was not significantly reduced, and excellent electrical conductivity was maintained. A relatively complicated flexible AgNW circuit was prepared by adding a patterned mask in the scrape-coating step. This is a low-cost method and can be used to form large films. The final product has excellent conductivity and some transparency and can provide new research directions for flexible electronic devices.

Silver Nanowires from Sonication-Induced Scission

Silver nanowires (AgNWs) have great potential to be used in the flexible electronics industry for their applications in flexible, transparent conductors due to high conductivity and light reflectivity. Those applications always involve size which strongly affects the optical and electrical properties of AgNWs. AgNWs of mean diameter 70 nm and mean length 12.5 μm were achieved by the polyol solvothermal method. Sonication-induced scission was used to obtain the small size AgNWs. The relationship between the size of AgNWs and the ultrasonic time, ultrasonic power, and concentration of AgNWs were studied. The results show that the length of AgNWs gradually reduces with the increase of the ultrasonic time and ultrasonic power, and with the decrease of concentration of AgNWs. Meanwhile, there is an existence of a limiting length below which fragmentation of AgNWs no longer occurs. Further, the mechanics of sonication-induced scission for the fragmentation of AgNWs was discussed.

Silver Nanowires Inks for Flexible Circuit on Photographic Paper Substrate

Silver nanowires (AgNWs) have inspired many research interests due to their better properties in optical, electric, and flexible applications. One such exploitable use is as the electrical conductive fillers for print electronics. In this paper, AgNWs with mean a diameter of 80 nm and mean length of 13.49 μm were synthesized using the polyol solvothermal method. A sonication-induced scission process was used to obtain AgNWs with a length range of 7.64–11.21 μm. Further AgNWs inks were prepared with the as-synthesized AgNWs as conductive fillers in anhydrous ethanol. The conductive inks were coated on resin coated photographic paper substrate using the knife coating process and dried at room temperature. The effects of the number of layers of AgNWs coating, the concentration of AgNWs, and the length of AgNWs on the microstructure and electrical properties of samples were investigated by scanning electron microscopy and using the four-point probe method. The results show that the conductivity of the AgNWs coating increases with the increase in the number of layers in the AgNWs coating, concentration and length of the AgNWs.

Flexible Transparent Conductive Film Based on Random Networks of Silver Nanowires

We synthesized silver nanowires (AgNWs) with a mean diameter of about 120 nm and 20⁻70 μm in length using a polyol process. The flexible transparent conductive AgNWs films were prepared using the vacuum filtration-transferring process, in which random AgNWs networks were transferred to a polyethylene terephthalate (PET) substrate after being deposited on mixed cellulose esters (MCEs). Furthermore, the photoelectric and mechanical properties of the AgNWs films were studied. The scanning electron microscopy images show that the AgNWs randomly, uniformly distribute on the surface of the PET substrate, which indicates that the AgNWs structure was preserved well after the transfer process. The film with 81% transmittance at 550 nm and sheet resistance about 130 Ω·sq-1 can be obtained. It is sufficient to be used as a flexible transparent conductive film. However, the results of the bending test and tape test show that the adhesion of AgNWs and PET substrate is poor, because the sheet resistance of film increases during the bending test and tape test. The 0.06 W LED lamp with a series fixed on the surface of the AgNWs-PET electrode with conductive adhesive was luminous, and it was still luminous after bent.

Emerging Novel Metal Electrodes for Photovoltaic Applications

Emerging novel metal electrodes not only serve as the collector of free charge carriers, but also function as light trapping designs in photovoltaics. As a potential alternative to commercial indium tin oxide, transparent electrodes composed of metal nanowire, metal mesh, and ultrathin metal film are intensively investigated and developed for achieving high optical transmittance and electrical conductivity. Moreover, light trapping designs via patterning of the back thick metal electrode into different nanostructures, which can deliver a considerable efficiency improvement of photovoltaic devices, contribute by the plasmon-enhanced light-mattering interactions. Therefore, here the recent works of metal-based transparent electrodes and patterned back electrodes in photovoltaics are reviewed, which may push the future development of this exciting field.