Silicene Discovered: Single-layer Silicon That Could Beat Graphene To Market 67
MrSeb writes "Numerous research groups around the world are reporting that they have created silicene, a one-atom-thick hexagonal mesh of silicon atoms — the silicon equivalent of graphene. You will have heard a lot about graphene, especially with regard to its truly wondrous electrical properties, but it has one rather major problem: It doesn't have a bandgap, which makes it very hard to integrate into existing semiconductor processes. Silicene, on the other hand, is theorized to have excellent electrical properties, while still being compatible with silicon-based electronics (abstract). For now, silicene has only been observed (with a scanning tunneling electron microscope), but the next step is to grow a silicene film on an insulating substrate so that its properties can be properly investigated."
Re:And now? (Score:4, Informative)
I apologize, I was hurried and didn't explain myself very well in the first post. You're correct, graphene (and apparently now silicene) has sp2 hybridization, but as the AC reply to your post suggests, it's the fact that carbon is group IV that gives it such interesting characteristics as a 2D structure. As a sidenote, I'd hesitate to assume silicene's electronic properties - silicon doesn't naturally form anything like graphite (i.e. stacks of loosely bonded monolayers) that I know of and since the properties of diamond and graphene are so different and I don't study monolayer materials, it'd be irresponsible of me to say "silicene will have X band gap" etc. Very interesting stuff, though, I'll be interested to see how this develops.
Abstract from one of the reports (Score:4, Informative)
"Because of its unique physical properties, graphene, a 2D honeycomb arrangement of carbon atoms, has attracted tremendous attention. Silicene, the graphene equivalent for silicon, could follow this trend, opening new perspectives for applications, especially due to its compatibility with Si-based electronics. Silicene has been theoretically predicted as a buckled honeycomb arrangement of Si atoms and having an electronic dispersion resembling that of relativistic Dirac fermions. Here we provide compelling evidence, from both structural and electronic properties, for the synthesis of epitaxial silicene sheets on a silver (111) substrate, through the combination of scanning tunneling microscopy and angular-resolved photoemission spectroscopy in conjunction with calculations based on density functional theory."
This is from Phys Rev Letters (DOI: 10.1103/PhysRevLett.108.155501
they show reasonably convincing LEED (low energy electron diffraction) and STM (scanning tunneling microscope) images of the putative hexagonal close packed array of Si atoms.
Re:Beat Graphene to Market? (Score:2, Informative)
Remember, "theorized to have" probably means something more like "we got some motherfuckin' mathematical models which say that this shit got all kindsa properties like".
Is there a version of "theorized to have" without incest and fecal matter? I think I'd be more interested in those models.
Re:Abstract from one of the reports (Score:2, Informative)
Note that the abstract linked to in the summary (http://prl.aps.org/abstract/PRL/v108/i15/e155501) speaks of "buckled" honeycomb. This is the surface of a Si crystal with diamond stucture. This is NOT the Si-equivalent of graphene, which has a flat or slightly wavy topology. I don't understand why everyone here is speaking of a graphene analogue, when it clearly is not!