After studying the mechanism of silver nanowire films, a team of researchers led by Shulin Ji from the Chinese Academy of Sciences’ (CAS) Hefei Institutes of Physical Science found that the greater the plasticity of the silver nanowire films, the more resistant they were to shear fracture.
The study outcomes were reported in the Nanotechnology journal.
Silver nanowire transparent conductive films display excellent application benefits for solar cells, sensors, touch screens, film heaters, and other fields as a result of their outstanding conductivity, good flexibility, and optical high definition.
But as one of the significant pliant electronic materials under extreme mechanical conditions, the properties of silver nanowire films seem to be unstable.
As far as thin films are concerned, the study of the fracture behavior of silver nanowires under shear stress included stress–strain theoretical simulation shear tests, in-depth microstructural analysis, and nano-indentation experiments.
The scientists discovered that by making use of various diameters of film and nanowire thicknesses to shift forces in the films, plastic deformation resulted in defect nucleation, and movement in the stress concentration area would result in variations in nanowire “necking.”
Hence, the addition of an ultra-thin metal buffer layer between the substrate and silver nanowire film to disperse the stress could enhance the shear fracture resistance of the films without impacting optical properties. Also, this could improve the films’ flexural stability.
Besides shear fracture, the research group also examined anti-scratch resistance and film uniformity under repeated bending. They noted higher uniformity compared to Indium Tin Oxide along with a surface hardness of 3H over thousands of bends.
This study offers a new concept for the large-scale industrial application of silver nanowire thin films. Also, it was financially supported by the Youth Innovation Promotion Association of CAS, the National Natural Science Foundation of China, and the Anhui Natural Science Foundation, among others.
Wang, M., et al. (2022) Fracture behavior of silver nanowire films during shear deformation. Nanotechnology. doi.org/10.1088/1361-6528/ac7731.