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Nano silver wire is used for transparent conductive film

Characteristics of nano silver wire:

1. Silver nano wire has high specific surface area, electrical conductivity and thermal conductivity.
2. Nano silver wire has surface plasmon effect: Surface plasmon refers to the electron density wave propagating along the metal surface generated by the interaction between freely vibrating electrons and photons that exist on the metal surface.
3. Silver is a good conductor of electricity, with low resistivity and high conductivity. Applying nano-silver wires to the conductive layer will draw out the collected current, which can reduce energy loss compared with TCO semiconductors.
4. If nano silver wires with a particle size smaller than the incident wavelength of visible light are used, the silver wires can be arranged very densely, and this technology can increase the current collecting area of ​​the silver electrode of the solar cell. It does not block the transmission of light, and at the same time, it can fully absorb light energy by taking advantage of the characteristics of light diffraction.

For transparent conductive film applications:
Due to its nanostructure size effect, nano silver wire has the characteristics of good conductivity, excellent light transmittance, flexibility and wide source of raw materials. The flexible TCF prepared with nano silver wires has the advantages of high transparency, low square resistance, good flexibility, low price, simple process, etc., and is considered to be the next generation of new materials in the field of flexible transparent conductive films.
After years of development, the preparation methods of nano silver wire flexible transparent conductive film mainly include spraying method, spin coating method, Meyer rod coating method and screen printing method. According to different manufacturing methods, the addition amount is different.
AgNWs flexible TCF is favored by the optoelectronic industry due to its excellent optical properties, electrical conductivity and flexibility, and is a new direction for industrial development.
In addition to the excellent conductivity of silver, nano-silver wires also have excellent light transmittance and flexibility due to the nano-level size effect, which provides the possibility to realize flexible, bendable LED displays, touch screens, etc., and A lot of research has applied it to thin-film solar cells. In addition, due to the large aspect ratio effect of silver nanowires, it also has outstanding advantages in applications such as conductive adhesives and thermally conductive adhesives.

The length of the nano silver wire produced by our Hongwu Nanomaterials Company is generally greater than 20 microns, and other lengths can also be customized. If you are interested in this, welcome to consult us.

Related products: metal nanowire,  silver  nanopowder

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Silver nanowire “ink” makes paper-based printing electronic products possible

By suspending tiny metal nanoparticles in liquids, Duke scientists are developing conductive inks for inkjet printers that can print inexpensive, customizable circuit patterns on any surface virtually .

Printed electronics have been widely used on a number of devices, such as anti-theft radio frequency identification (RFID) tags that are usually found behind new DVDs. It currently has a major drawback: in order for the circuit to work, it must first be heated to fuse all of the nanoparticles into a single conductive filament, which makes it impossible to print circuits on cheap plastic or paper.

A new study by Duke University researchers shows that adjusting the shape of the nanoparticles in ink eliminates the need for heating.

By comparing the conductivity of thin films made from different shapes of silver nanostructures, the researchers found that electrons made of silver nanowires are much easier to fabricate than films made of other shapes such as nanospheres or microdisks. In fact, the flow of electrons through a film made of nanowires is so easy that they can be used in printed circuits without melting them together.

Benjamin Wiley, an assistant professor of chemistry at Duke University, said: “the conductivity of nanowires is 4000 times higher than that of commonly used silver nanoparticles that can be found on printed RFID tags. So if you use nanowires, then you don’t need to heat the printed circui to such a high temperature that you can use cheaper plastic or paper.”

Wiley added: “in addition to these silver nanowires, I really don’t think there is anything else that can be simply printed out like this. Without any post-processing, it can be directly conductive.”

Applications of these types of printed electronics may go far beyond smart packaging. Researchers envision using this technology to make solar cells, printed displays, LEDs, touch screens, amplifiers, batteries, and even some implanted bioelectronic devices.

Wiley said that silver has become a raw material for the manufacture of printed electronic materials, and many recent studies have shown the measurement of the electrical conductivity of silver nanostructure films of different shapes. However, experimental errors make it difficult to make direct comparisons between different shapes, and there are few reports that relate the conductivity of the film to the total mass of silver used, which is an important factor when using expensive materials.

“We want to eliminate any extra materials from ink, just focus on the silver content in the film and the link between the nanostructures as the only source of variation,” said Stewart, another graduate student.

Stewart uses known recipes to make silver nanostructures with different shapes, including nanoparticles, microchips, and short and long nanowires. These nanostructures are then mixed with distilled water to make a simple “ink.” He then invented a quick and easy way to make films using glass slides and double-sided adhesive tapes that can be easily found in any laboratory.

Stewart said: “We used punches to punch wells out of double-sided tape and stick it to the glass.” By adding a precise amount of ink to each well of the tape, the well was then heated to a temperature of The relatively low temperature at which the water evaporates or the relatively high temperature at which the structure begins to melt, he has obtained a variety of films for testing.

The research team said that they are not surprised that the long nanowire film has the highest conductivity. Electrons usually pass easily through a single nanostructure, but they tend to get stuck when they have to jump from one structure to the next, Wiley explained, while long nanowires greatly reduce the number of electronic “jumps.”

However, they were surprised by the intensity of this change. “The resistivity of long silver nanowire films is orders of magnitude lower than that of silver nanoparticles, and only ten times larger than pure silver,” Stewart said.

The team is now experimenting with aerosol inkjet printers to print silver nanowire inks in available circuits. Wiley said that they also want to explore whether silver-plated copper nanowires can produce the same effect, which is much cheaper than pure silver nanowires.

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Transparent flexible circuit based on silver nanowire conductive material

With the continuous development of technology, various transparent and flexible electronic devices have developed rapidly. However, compared with transparent flexible conductive materials, there are still many problems in the research of transparent flexible circuits. The research of many transparent flexible circuits only stays at the level of transparent substrate and opaque circuit. Recently, Professor Sun Jing of Dalian University has designed a transparent flexible circuit by using polydimethylsiloxane (PDMS) as a flexible substrate and silver nanowires (AgNWs) as a conductive material, which overcomes the previous transparent flexible circuit part. The drawback of transparency is the realization of a truly transparent transparent circuit. The related research work was published in Chemical Communications and was selected as the bottom article of the 5418, Volume 39, issue of 2018.

The researchers first performed experiments on PDMS, using the spin coating technique to spread the AgNWs solution evenly on the hydrophilically modified PDMS surface. The transmittance and resistance of the transparent flexible conductive material reached 90.86% and 3.22 Ω·sq-1, respectively. It is at the leading level in the field of transparent flexible conductive materials.

The research team used the mature microfluidic control technology to create holes with various complex patterns on the transparent flexible substrate PDMS surface, and the precision can reach micron level; then AgNWs are spread into these holes to make them high at the same time. Electrical conductivity. The transparent flexible circuit thus prepared has a strong wear resistance due to the protection of the channel to the AgNWs.

The transparent flexible circuit not only has good optical and electrical properties, but also has good mechanical properties. They used LEDs and ordinary dry batteries to test their electrical conductivity. The results showed that the conductivity was good. After the 180-degree inward and outward bending, 720-degree distortion and tensile test of the circuit, the brightness of the LEDs remained basically unchanged. change. The researchers further explored the application of the transparent flexible circuit, deposited Pd nanoparticles on the AgNWs of the circuit by electrodeposition, and used it to detect glucose. The results show that the sensor has high sensitivity to glucose detection.

The originality of this research is to solve two problems in the preparation of transparent flexible circuits: (1) to achieve a completely transparent flexible circuit; (2) to design circuit patterns as desired. The transparent flexible electrode prepared by the research is simple in preparation, controllable in quality and excellent in technical indicators, which can greatly promote the development of wearable electronic devices.

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Nanowires

Definition: The nanowires can be defined as a one-dimensional structure with a limit of 100 nanometers in the transverse direction (longitudinally unrestricted). Suspended nanowires indicate that the nanowires are fixed under vacuum conditions. Typical aspect ratios of nanowires are above 1000, so they are often referred to as one-dimensional materials.

Physical properties of Nanowires:

1. Mechanical properties

Normally, as the size decreases, the nanowires will exhibit better mechanical properties than large pieces of material. Strength becomes stronger, toughness becomes better.

2. Conductive properties

With the significant changes in mechanical properties, the electrical properties of nanowires are also significantly different from those of bulk materials. The conductivity of nanowires is expected to be much smaller than that of bulk materials. The reason is that when the cross-sectional dimension of the nanowires is smaller than the average free path of the bulk material, the scattering effect of the carriers on the boundary will be highlighted. The resistivity will receive a serious effect of the boundary effect. The surface atoms of the nanowires are not sufficiently bonded to the atoms in the bulk material, and these surface atoms that are not sufficiently bonded are often the source of defects in the nanowires, so that electrons can not pass smoothly The nanowires have lower conductivity than body material.
The conductivity of nanowires is expected to be much smaller than that of bulk materials. This is mainly caused by the following reasons. First, when the line width is less than the free electrons of free radicals, the scattering of carriers on the boundary will appear. For example, the average free path of copper is 40 nm. For copper nanowires with a width less than 40 nm, the mean free path will be shortened to line width.
At the same time, because of the scale of the reasons, the nanowires will also reflect other special properties. In carbon nanotubes, the movement of electrons follows the principle of ballistic transport (which means that electrons are free to travel from one electrode to another). In the nanowires, the resistivity is severely affected by the boundary effect. These boundary effects come from the atoms on the surface of the nanowire, which are not fully bonded as those of those atoms in the bulk material. These atoms that are not bonded are usually the source of defects in the nanowires, making the nanowires’ conductive capacity lower than the bulk material. With the decrease of nanowire size, the number of surface atoms increases relative to the number of atoms, so the boundary effect is more obvious.
Further, the conductivity will undergo energy quantization. The nanowires are connected between the electrodes, and scientists can study the conductivity of nanowires. By measuring the conductance of the nanowires at the time of stretching, the scientists found that when the length of the nanowires was shortened, its conductivity was also reduced in the form of ladder, with a Langjian constant G between each order.

Application of Nanowires:

In the electronics, optoelectronics and nanoelectromechanical devices, nanowires may play a very important role. It can also be used as an additive in composites, in a quantum instrument, a field emitter, and a biomolecule nanosensor.

1. Manufacture of electronic equipment
Some early experiments have shown that nanowires can be used in next generation computing devices. In order to make effective electronic elements, the first important step is to chemically method the nanowire doping. This has been implemented on nanowires to produce P-type and N-type semiconductors. The next step is to find the way to make the most simple electronic device for PN junctions. This can be done in two ways. The first is a physical method: put a P-line into an N-line. The second method is chemical: mix different impurities along a line. The next step is to build a logic gate. By simply connecting several PN sections together, the researchers have created all the basic logic circuits: the AND, or the NAND gate can already be crossed by the nanowires. The nanowire crossover may be important for the future of digital computing.

2. Solar energy conversion
The nanowires are able to naturally gather sunlight into a very small area of ??the crystal, which is 15 times the intensity of ordinary light. Since the diameter of the nanowire crystal is smaller than the wavelength of the incident sunlight, the resonance of the interior of the nanowire crystal and the surrounding light intensity can be caused. The study found that the photon emitted by resonance is more concentrated (solar energy conversion is in the process of disseminating the photon), which helps to improve the conversion efficiency of solar energy, making the nanowire-based solar cell technology has been really improved.

3. Promote chemical reactions
Researchers built the nanometer “tree” electrode into the water, and then use the simulated sunlight to illuminate and measure the output of the electricity. The results show that this vertical branch structure can not only capture a lot of solar energy, but also to maximize the increase in hydrogen production. Because in the plane structure, the bubbles must be large enough to float the surface, and the vertical structure can quickly extract very small hydrogen bubbles. The researchers said that this vertical branch structure can provide a chemical surface reaction area of ??400,000 times higher than the surface area. Researchers also have more ambitious goals, their eyes staring at the artificial photosynthesis. In natural photosynthesis, plants not only absorb sunlight, but also absorb carbon dioxide and water, resulting in carbohydrates for their own growth. Researchers hope to one day be able to imitate this process, the use of nano “forest” to absorb the atmosphere of carbon dioxide.

4. Microcell manufacturing
Scientists have made an important step in the manufacture of microcells, and they have developed a microcell with a vertically aligned nickel-tin nanowire, which is evenly wrapped around a multi-cell called PMMA Body material, which is commonly known as plexiglass. The main role of PMMA is insulation, when the current through, it can protect the inside of the nanowires from the reverse electrode. This battery is shorter than the average lithium battery charging time, other performance is also more excellent.

HW NANO, a high-tech enterprise focusing on manufacturing, research, development and processing of nanoparticles and nanowires.
High quality silver nanowires,copper nanowires, ZnO nanowires, SiC nanowires, precious metals nanowires with multi specification are available. As for olutions, it would be customized.

Related reading:Metal Nanowires Suppliers  Silver Nanowires

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Silver Nanopowder and Silver Nanowires Application Guide

Silver Nanoparticle application guide:
Common stirring to disperse the silver nanopowder is very difficult. At least more than 30 minutes with an ultrasonic disperse. Using pvp coated or a fatty acid coated is just in order to improve the dispensability of the silver powder. Generally based on customer requirements have been handled well in advance, and then customer can be used directly. Unmodified silver nanopowder’s dispersion, generally need to add some non-toxic surfactants, such as washing fruits and vegetables detergent. Before to disperse pvp-coated silver nanopowder, it is suggested to wetted with ethanol and then add water to stir, without affecting the customer process, add a few drops detergent mixing, the effect is also very good.

Silver Nanowires application guide:
Generally we maintain silver nanowires inventory in powder form. We could also maintain dispersed in ethanol or IPA. Just depends on the customer required. Shipments in solvents may require additional lead time. We can provide silver nanowires in different concentration according to customer request. The solvent include ethanol, isopropanol, diethylene glycol, water, terpineol and so on. And silver nanowires is very stable, not easy to be oxidized, could use it under the room temperature. But after open it, please sealed it up at soon as possible so that will not affect the powder quality when exposed to the air in long time.

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Silver nanowires is considered as very promising candidates in flexible electronic

Silver nanowires has been attracting more and more attention because of their intriguing electrical, thermal, and optical properties.Silver has the highest electrical conductivity among all the metals, by virtue of which Ag NWs are considered as very promising candidates in flexible electronics. Ag NWs thin film used as transparent electrode showed equal merit or better than that as compared with sputter-coated ITO in solar cells.

Ag NWs suspension can be directly and uniformly coated onto PET at room temperature without and hydrophilic or hydrophobnic pre-treatment of PET or coating materials, and no surfactants are required. However, the solvents are found to be very important to the uniformity of films. We have dispersed Ag NWs in distilled water, surfactants aqueous, ethylene glycol, methanol, and isopropanol. After 1h sonication, all of these suspentions agglomerated in 5 h. On the other hand, Ag NWs show much better dispersibility, and are easier to re dispersion in methanol and isopropyl alcohol than in aqueous solution.

Using nail polish, NW thin film have not caught up with ITO yet, this proposed fabrication method is simple and easy to be scaled up for large films, which is one of the key issues for applying this technology to commercial applications.

Low temperature solution-deposited Ag NWs networks embedded in ITO-NP matrices demontrate significant improvement in surface morphology, mechanical adhesion, and flexibility while maintaining the sheet resistance and transmittance values necessary to replace conventional sputtered ITO thin films.

 

Related articles: Copper Nanowires Used in Thin Film Solar Cells

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What will replace ITO？ Metal mesh? Or silver nanowires?

What is ITO?
Indium Tim Oxide(ITO), is a thin-film material, usually used in LCD,PDP,EL/OLED, Touch Panel, Solar Cells and transparency electrode of other electronic instruments.

ITO is now widely used in electronic products, but the future of electronics, such as mobile terminals, wearable devices, smart appliances, etc. Touch panel is hoped to become the large-size, cost-reduction and flexible. This is bound to promote the new materials to replace traditional ITO.
Traditional ITO thin film can’t used in flexible application, and its inherent problems—-conductivity and light transmittance are difficult to overcome. Thus, numerous manufacturers begin to find the substitutes for ITO, such as silver nanowires, metal mesh, carbon nanotubes(CNTs) and graphene.
From technology and marketization level, metal mesh and silver nanowires will be the two major roles in new-developing touch technology.

ITO alternatives – silver nanowires
What is the silver nanowires?
Silver nanowires (SNW, silvernano wire) technology, the silver nanowires ink material is applied on plastic or glass substrate, and then using the laser lithography technology to portray into a transparent conductive film with nanoscale silver line conductive network pattern.
The Advantages and Disadvantages of Silver Nanowires Advantages:
1.the production process is simple and good rate.
2.since the line width is small, the conductive thin film made of silver nanowires technique can achieve higher light transmittance than the one made of a metal grid technology.
3.compared to the metal mesh film, silver nanowires films own a smaller radius of curvature and the resistance change rate is small while bending, the application on devices with surface display, such as smart watches, bracelets, etc, has more advantages.
4.besides excellent electrical conductivity than silver, because of the nanoscale size effect, silver nanowires also have excellent transparency and resistance to flex.
5.large aspect ratio of silver nanowires effect makes its applications in conductive plastic, thermal plastic and other fields also have outstanding advantages.

Disadvantages:
With the severe diffuse reflection light irradiation in outdoor scenes, the screen reflective strongly, you can not see the screen clearly.

Silver nanowires Status
1. although silver nanowires has slightly high raw material costs, its preparation is simple, thus the overall cost is not high. And diffuse phenomenon can use some techniques to reduce;
2. the silver nanowires coated with a high refractive index material film;
3. blackening silver nanowires surface;
4. Reduce the reflective intensity;
5. roughened silver nanowires.