Researchers at the University of Glasgow have devised a method that uses inexpensive copper to produce large-area graphene some 100 times more cheaply than via traditional methods.

Graphene is often produced with standard copper foils by a process known as chemical vapor deposition (CVD), which turns gaseous reactants into a film of graphene on a substrate. The research team—led by Dr. Ravinder Dahiya, reader and EPSRC Research Fellow in the university's Electronics and Nanoscale Engineering Research Division—used a similar process to create high-quality graphene across the surface of commercially available copper foils of the type often used as negative electrodes in lithium-ion batteries.

Dr. Ravinder Dahiya, University of Glasgow.As it turns out, the ultra-smooth surface of the commercially available copper they chose provided what they say is an excellent bed for the graphene to form.

When the team compared the electronic transport properties of the graphene film with that synthesized from commonly used standard copper foils in CVD, they observed an improvement in the electrical performance of the transistors.

To study the optical properties, the researchers transferred CVD-based graphene to transparent flexible substrates using a hot lamination method and performed large-area optical scanning. They obtained a transmittance modulation up to two times more efficient (at 700 nm) using smooth-copper graphene in supercapacitors operating as optical modulators.

The commercially available copper the researchers used retails for $1.00 per square meter, compared to around $115 for a similar amount of copper currently used in graphene production. Further, the researchers say, their methodology does not require chemical treatment or deposition of copper foils. Traditional processes using more expensive copper often require preparation before use, adding to costs.

Dahiya says he is hopeful that the advances could help propel industrial adoption of graphene, which so far has been limited by the expense of producing it.