Transparent Conductive Coatings


Gradient Transparent Conductive Coating

Recently, we have developed a novel method to integrate carbon nanotubes (CNT)s onto a polymer substrate with "built-in" conductivity features based on Emitech's proprietary CNT spraying technology. Our preliminary results demonstrate an excellent incorporation of CNTs in the polymeric transparent substrate due to the softening of the polymer surface layer upon CNT spraying. Thus, the CNT film (with low resistance/ high transparency) is naturally integrated to the polymer matrix (from spraying side) providing a "built in" conductivity feature. As distinct from other CNT films deposited on plastic substrate forming bi-layer structures and ITO deposited films, our gradient coating is extremely durable, which can withstand rigorous bending and harsh environmental conditions.

Image of flexing of CNT-composite film (left panel) and sheet resistance values as a function of the bending numbers (right panel).

The figure shows the image of the flexing of CNT-composite film (left panel) and sheet resistance values as a function of the bending numbers (right panel).  Gradient coating demonstrates transmittance   T=70% (550 nm) at sheet resistance R= 30Ω/sq (without optimization). This is one of the best T/R performances for CNT based film reported in the literature. With optimal deposition specification and appropriate post-deposition treatment T/R performance can match and exceed ITO metrics.  

PERCO Transparent Conductive Coating

We are developing a new method of the fabrication of transparent conductive coating (TCC) based on a micro-percolative conductive grid (named PERCO) with a T/R performance exceeding current T/R metrics for regular (square pattern) conductive grids and other continuous TCC, including ITO.

The main concept of PERCO technology is based on the fundamental principle of the percolation phenomenon which can be applied to the micro-grid patterning, providing substantial improvement of T/R performance and suppression of light diffraction. Algorithmic micro-grid patterning can be implemented by various deposition techniques (printing, spraying, coating), using different conductive materials (metals, metal nanowires, carbon nanotubes, graphene, conductive polymers) on glass and flexible plastic substrates. Experimental results and modeling show T= 92-95% and R= 2-5 Ω/sq without optimization. Patent application was filed and assigned to Corish, Inc. (Emitech subsidiary) for the following technology commercialization.