For some time, arrays of silver nanowires (AgNW) have been considered promising candidates to replace indium tin oxide because they are flexible and because each wire on its own is highly conductive
As the market for liquid crystal displays and other electronic components continues to drive up the price of indium—the material used to make the transparent indium tin oxide-based electrodes in these devices—scientists are looking for a less expensive and more dynamic alternative, especially for use in future flexible electronics.
Besides its high price, indium tin oxide (ITO) has several disadvantages - it is brittle and therefore useless for use in flexible displays and solar cells, and in addition there is a shortage of indium, which is found mainly in the Asian continent. Moreover, the production itself of layers of this material is quite inefficient.
Now, researchers from the University of California, Los Angeles (UCLA) report in the scientific journal ACS Nano that they have succeeded in developing a unique method for producing transparent electrodes based on silver nanowires in combination with other nanomaterials. The new electrodes are flexible and have a high level of conductivity and overcome the limitations inherent in tin-indium oxide.
For some time, arrays of silver nanowires (AgNW) have been considered promising candidates to replace indium tin oxide because they are flexible and because each wire on its own is highly conductive. However, complex treatment methods are usually required in order to fuse and cross these arrays to obtain low resistance and good adhesion to surfaces. In order to solve this, the researchers demonstrated that by fusing silver nanowire arrays with metal oxide nanoparticles and organic polymers, Highly transparent conductors can be efficiently produced.
The head of the research team, Professor of Materials Science and Engineering Yang Yang, explains: "In this study, we were able to demonstrate a simple and effective method for obtaining composite layers of highly conductive silver nanowire arrays with optical transparency and excellent mechanical properties. This is the best solution: a transparent electrode suitable for a wide variety of bedding."
Scientists are able to easily spray a surface of the nanowires to obtain a transparent sheet, but the challenge is to allow the silver nanowires to stick to the surface better without using extreme temperatures (200 degrees Celsius) or high pressures, conditions that make the nanomaterial less suitable for sensitive organic materials used Widely used in the production of flexible electronic components. In order to meet this challenge, the researchers developed a low-temperature method for preparing high-performance transparent electrodes from silver nanowires by sputtering a coating with a unique combination of nanomaterials.
First, the researchers spray a commercially available solution of silver nanowires onto a surface. In the next step, they treat the nanowires with a solution of titanium dioxide nanoparticles to obtain an integrated layer. While the layer dries, capillary forces stick the nanowires together, thus improving the conduction quality of the layers. In the next step, the researchers coat the The resulting layer is a layer of conductive polymer in order to increase the adhesion of the wires to the surface.
The composite combinations of the silver nanowire arrays are extremely conductive, have optical transparency and excellent mechanical properties. The research team also built solar cells based on the transparent electrodes and found that their performance is comparable to solar cells composed of indium dioxide.
