Finding the Impact of Impurities on Graphene
Some people may not always think about it, but impurities are important to our way of life. The changes impurities can cause in many materials has enabled and improved many technologies we have come to rely on. Now researchers at Rice and Osaka universities have found how much impurities can disrupt graphene, a material many hope will be central to future technologies.
Graphene is an atom-thick sheet of carbon with special electrical properties, including great electron mobility. Of course for those properties to be useful in future technologies, they must persist, but the researchers have found that they can be greatly affected by impurities from the environment. The researchers grew a sheet of graphene and transferred it to an indium phosphide substrate for this research. When femtosecond laser pulses struck the graphene, the indium phosphide reacted by emitting terahertz radiation that passed through the graphene. Using a spectrometer, the researchers were able to detect imperfections as small as an oxygen molecule, as they affect the electric field of the graphene, and disrupted the terahertz radiation.
Of course the knowledge of how much graphene can be affected by imperfections is going to impact the development of technologies that may use it. One potential technology may be to actually adapt this experiment's design as a highly sensitive gas sensor.
Source: Rice University