Hybrid Polymer Composites with Silver Nanowires:
Transparent, conductive and stretchable

Transparent conductive layers are a key component of microelectronics and display technology. Especially applications on flexible polymer substrates are a challenge for established materials such as indium tin oxide (ITO) or aluminum doped zinc oxide (AZO) when it comes to bendable components.

Due to their high aspect ratio, silver nanowires (Ag nanowires, AgNW) make it possible to combine metallic conductivity and optical transparency with minimal material usage. Unprotected, however, AgNWs are mechanically unstable and practically unusable.

Composite resins can be produced from AgNWs and hybrid polymers (ORMOCER®s). The resulting layers have a surface conductivity around 4.8 Ω square with a transparency of more than 75 %. The specific conductivity of 1.40 E-04 Ω cm is in the range of dense sputtered ITO.

Due to their mechanical flexibility, these functional layers are not only foldable, they can also be stretched within limits while maintaining their conductivity. In addition, the underlying hybrid polymer layers can be laterally structured by UV lithography. This unique combination of material properties opens up perspectives for novel applications such as stretchable displays.

Photolithographically structured AgNW composite layer (left) and surface conductivity as a function of material strain (right).

Composite layer surface conductivity
© Fraunhofer ISC