Human life has unknowingly entered the "nano era," and nanotechnology can be applied to countless useful devices.
These devices typically use electrodes made by coating a thin layer of conductive material onto a glass or ceramic substrate. However, these electrodes are fragile, lack flexibility, and use expensive and hard-to-find materials, making them quite difficult to manufacture.
Therefore, people have turned their attention to an alternative material: silver nanowires.
Silver nanowires have been successfully used as electrodes in various electronic devices. However, they are susceptible to corrosion from heat, light, and moisture. Corrosion can cause pits and holes, or "etching," on the nanowire surface, negatively impacting their electrical, mechanical, and optical properties. Etching is particularly detrimental to the performance of silver nanowire-based devices and can even lead to device failure.
A new study has developed a method for fabricating ultrathin shells around silver nanowires, achieving remarkable stability and efficiency.
Researchers initially chose gold as the protective shell because it can resist heat, light, and moisture.
Its structure is also similar to that of silver, which facilitates the growth of ultrathin gold layers on the surface of silver nanowires. However, charged gold atoms may react with the silver itself, forming pores or voids, which is clearly problematic.
The team solved this problem by selecting a chemical substance that interacts with charged gold atoms, effectively suppressing the formation of pores.
Experiments show that:
When exposed to air, uncoated silver nanowires showed severe damage and deterioration after 10 days. Gold-plated nanowires, however, remained unchanged even after 6 months.
In performance testing of flexible transparent electrodes, both types of nanowires were exposed to high temperature and high humidity. The uncoated nanowires failed after 12 days, but the performance of the gold-plated silver nanowires was comparable to that of top-tier commercial nanowires.
In performance testing of optical devices, gold-plated nanowires exhibited high performance over 21 days. In contrast, untreated silver nanowires showed a decline in efficiency within one week and ultimately failed.
The price of nanowires combining gold and silver will naturally be higher. However, due to their excellent conductivity, nanoscale size, and superior light transmittance and flexibility, they will play a significant role in fields such as flexible foldable screens in the future.
