Graphenea granted patent on graphene transfer
Graphenea was granted a patent for a method of transfer of large-area graphene. In particular, the patent refers to transferring graphene grown by chemical vapor deposition (CVD) from a metal foil to an insulating substrate. As CVD is the most promising way of growing large, high quality graphene sheets, which are most often useful only on insulating substrates, this could be a key patent in the graphene industry. The granted patent is the first for Graphenea.
Graphene, possessing a vast array of exotic properties such as high electronic mobility, extraordinary thermal conductivity, great strength, flexibility, and transparency, is an ideal candidate for a wide variety of novel applications. If all the unusually excellent properties of graphene are industrially exploited, the material could have applications in electronics (high frequency devices, transistors, etc.), energy (solar cells, batteries, supercapacitors, etc.), touch screen and display technology (TV screens, mobile phones, etc.), sensors, and other technologies. To access graphene’s superior properties, however, one needs to obtain large high-quality sheets of it.
The most appropriate known method of obtaining such large sheets is CVD. In CVD a source of carbon is introduced into a chamber holding a metal catalyst substrate. Under specific controlled conditions (pressure, temperature), the carbon forms smooth single atomic layers on all sides of the metal foil. CVD growth of graphene has, since its introduction in 2009, been optimized and perfected, already in 2010 featuring 30-inch graphene layers. More than 95% coverage of the substrate can be obtained on copper.
After growth on a metal, the graphene in most cases needs to be transferred to a useful substrate, such as an insulator (SOI). Transfer of such a large yet thin film is obviously a challenge which often results in an imperfect final product. Thus, to fully unlock the potential of CVD growth, the transfer method needed to be optimized.
US patent number 20140001152, entitled “Method of manufacturing a graphene monolayer on insulating substrates”, describes the procedure by which Graphenea makes some of the world’s highest quality large-area graphene on arbitrary substrates.