London, Nov 11 : Scientists at UCLA's California NanoSystems Institute (CNSI) have come up with a new method for the large-scale production of graphene sheets, which are used as nanomaterial.
Graphene is created when graphite is reduced down to a one-atom-thick sheet, which can be used as electrodes for solar cells, for use in sensors, as the anode electrode material in lithium batteries and as efficient zero-band-gap semiconductors.
However, as the scientists face difficulty in creating single-layer samples for use in experiments, much has not been done as far as research related with graphene is concerned.
But now, scientists led by Yang Yang, a professor of materials science and engineering at the UCLA Henry Samueli School of Engineering, scientists have developed a method in which graphite oxide paper is placed in a solution of pure hydrazine, which then turns graphite oxide paper into single-layer graphene.
Researchers have claimed that the graphene produced from the hydrazine solution is a more efficient electrical conductor.
Field-effect devices display output currents three orders of magnitude higher than previously reported using chemically produced graphene.
"We have discovered a route toward solution processing of large-scale graphene sheets. These breakthroughs represent the future of graphene nanoelectronic research," Nature quoted co-author Vincent Tung as saying.
It is possible to control the coverage of the graphene sheets by altering the concentration and composition of the hydrazine solution.
The hydrazine method also preserves the integrity of the sheets, producing the largest-area graphene sheet yet reported, 20 micrometers by 40 micrometers.
"These graphene sheets are by far the largest produced, and the method allows great control over deposition. Chemically converted graphene can now be studied in depth through a variety of electronic tests and microscopic techniques not previously possible," said one of the co-authors of the study.
"This technology (hydrazine reduction) utilizes a true solution process for graphene, which can dramatically simplify preparing electronic devices. It thus holds great promise for future large-area, flexible electronics," said Yang.
The study is published online in the latest issue of journal Nature Nanotechnology.