Multipurpose nanocomposite resist for free-standing transparent conductive thin films

PEREZ-MORELO, D. J.; CHEHADE, PABLO; MARTÍNEZ, EDUARDO DAVID; DIAZ SCHNEIDER, JUAN IGNACIO; GRANJA, LETICIA PAULA

Flexible and Printed Electronics

IOP Publishing Ltd

Lugar: Bristol; Año: 2022 vol. 7

Nanocomposites formed by silver nanowires (AgNWs) embedded in a polymer matrix are aconvenient way to deposit thin films with electrical conductance and high transparency ondifferent substrates. Nanocomposite resists containing AgNWs in a polymethyl methacrylatesolution can be effectively used to produce conductive coatings in a straightforward manner.Here, we show that by adding a sacrificial layer of polyvinyl pyrrolidone (PVP) on a glasssubstrate, prior to the nanocomposite resist, it is possible to obtain large-area free-standingfilms of about 450 nm with electrical conductance and high transparency. The films can betransferred to different surfaces and materials including non flat substrates. The formation ofconductive stacks by piling two layers was also demonstrated. The optical, electrical, andstructural properties of these free-standing films were studied obtaining films withtransmittance T(%)=78% at 550 nm, sheet resistance Rs= (670±40) Ω·sq-1and surfaceroughness Ra= (50±10) nm. We studied the strain resistance behaviour of films transferred topolyethylene terephthalate sheets under bending tests finding a sensitivity of (0.51±0.01)Ω·deg-1and a gradual increase in the resistance during cycling. In addition, thin flexiblesupports can be added by covering the nanocomposite film with PDMS prior to its release,enhancing the mechanical robustness and improving the manipulation of the films.