A lot of hype is out there about both of them (especially the latter) and I was wondering if there is more concrete information about them other than the news IBM posted on a circuit 2 years ago and the patent war about Graphene transistors involving Samsung and IBM among others. Also, what's up with Silicene? Is it of any importance or is the hype there only because it is based on Si?
When silicene is buckled on the substrate it has a substantial band gap or in other words it can be turned on or off thus making it appropriate for digital applications. Graphene doesn't have a band gap so it isn't so good for digital circuits. Although techniques have been developed to produce a band gap and transistors have been made, they say that the processes are too expensive to be practical for at least for the next 20 years. The first p and n materials necessary for transistors were only made in November of 2012 out of silicene so it is still in the baby stages. It is so promising because it is compatible with existing cpu and memory chip production technology which suggests that it could be turned into chips much sooner than graphine. If you want the references just google silicene and look for the research papers after July 2012.