Although the use of camera lash has been reported in CNT, Si nanowire and conducting polymer. This work still gave me a big shock.
http://pubs.acs.org/doi/abs/10.1021/ja902348k
Researchers from Northwestern University (the alma mater of my master adviser) had invented a new way to reduce graphite oxide. They used the commercial camera's flash light to irradiate the GOs and make them back to graphite and accounted for this effect by using photothermal heating mechanism. They found that the flash method is effective enough to compare with themal annealed samples. The basic principle is about the water evaporation from the GO, and the enough photo energy to trigger the deoxygenating process.
Taking advantage of flash light, they even make a photomask to define the device region. This is a very useful method for GO approach, and they demonstrated again that the camera flash is able to be a tool for reduction proecess.
I just wondering why the flash light irradiation in ambient condition could be a reducing agent for GO while being a oxide agent in other cases. @_@
Over 1 square centimeter graphene debut!!
No doubt this accomplishment is definitely an enormous progress for graphene research.
A famous group from UT Austin, lead by Rodney S. Ruoff, a leader who first carved up graphite into graphene in 1998, he also wrote a review article in Nature Nanotechonlogy in just few months earlier.
They found if the growth substrate for CVD graphene is replaced by a copper foil, the growth of graphene would be self-limited, which means it is hard to build the second layer on the top of the first layer graphene. With the help of the poor carbon solubility in copper during the synthesis process, the graphene is formed continuously across a vast area of substrate. Eventually, they concluded that the precipitation process of carbon on the surface of copper is suppressed at the high temperature, which enabled a large continuous graphene to be obtained.
The realization of getting a wafer scale and atomically thin graphene is a great progress, however, the absence of band gap in SLG has strongly limited the potential application in electronic industry. Nowadays, a vigorous trend is to open a band gap in graphene electronic device without degrading the transport properties. As far as I know, there are many groups are eagerly working on band gap engineering of graphene, one of these possibility is bilayer graphene, which has been shown to be able to get a band gap under the dual gate configuration. I believe that one day the dream of wafer scale CVD bilayer graphene will be realized. Unfortunately, in spite of my previous work is related to build a CVD system, I don't have chance and enough time to work on it...
