With the advent of folding phones from brands such as Samsung and Huawei, the topic of flexible transparent conductive films and flexible transparent conductive materials has risen to an unprecedented level. On the road to commercialization of folding mobile phones, there is an important material that must be mentioned, that is, the “SILVER NANOWIRE”, one-dimensional structure with good bending resistance, high light transmittance, high electronic conductivity and thermal conductivity
Why is it important?
The silver nanowire is a one-dimensional structure with a maximum lateral direction of 100 nm, no longitudinal limitation, and aspect ratio over 100, which can be dispersed in different solvents such as water and ethanol. In general, the longer the length and the smaller the diameter of silver nanowire, the higher the transmittance and the smaller resistance.
It is considered to be one of the most promising flexible transparent conductive film materials because the high cost and poor flexibility of traditional transparent conductive material-indium oxide (ITO). Then carbon nanotubes, graphene, metal meshes, metal nanowires, and conductive polymers are used as alternative materials.
The metal silver wire itself has the characteristics of low resistivity, and thus has been widely used as an excellent conductor in LED and IC packages. When it is transformed into a nanometer size, it not only retains the original advantages, but also has a unique surface and interface effect. Its diameter is much smaller than the incident wavelength of visible light, and can be densely arranged into ultra-small circuits to increase the current collection. Thus it is highly favored by the mobile phone screen market. At the same time, the nano size effect of the silver nanowire also gives it excellent resistance to winding, is not easy to break under strain, and fully meets the design requirements of flexible devices, and is the most ideal material to replace the traditional ITO.
How is the nano silver wire prepared?
At present, there are many preparation methods for nano silver wires, and common methods include stencil method, photoreduction method, seed crystal method, hydrothermal method, microwave method, and polyol method. The template method requires prefabricated template, the quality and quantity of the pores determine the quality and quantity of the nanomaterials obtained; the electrochemical method pollutes the environment with low efficiency; and the polyol method is easy to obtain due to simple operation, good reaction environment, and large size. Most people are favored, so a lot of research has been done.
Based on years of practical experience and exploration, Hongwu Nanotechnology team has found a green production method that can produce high-purity and stable silver nanowires.
As the most potential alternative to ITO, nano silver wire, if it can solve its early constraints and give full play to its advantages and achieve full-scale production, the flexible screen based on nano-silver wire will also usher unprecedented development opportunities. According to public information, the proportion of flexible and foldable soft screens is expected to reach more than 60% in 2020, so the development of nano-silver lines is of great significance.