Graphene and porous graphene are very promising materials, which have been widely studied for electronic applications. It was expected, that graphene, porous graphene and graphene-like molecules will effectively replace silicon. Despite it superior properties relative to traditional materials, however, the field-effect transistors based on graphene or graphene nanoribbons build so far via top-down approaches have low on/off ratios. On the other hand, molecular nanotransistors build with precisely know atomic structures resembling graphene were synthesized only very recently. In order to pave the way towards the industrial fabrication of molecular nanotransistors, we have investigated the chemisorption of graphene-like molecules on the 7x7 reconstructed Si(111) surface via large-scale density functional theory (DFT) calculations including van-der-Waals corrections. We found, that Si(111) is a very promising candidate to serve as a substrate for the deposition of coronene-based molecular transistors. Moreover, our results show, that various adsorbate molecules prefer specific binding sites on the Si(111) surface, and van-der-Waals forces considerably change the energetics. By following the template of the Si(111) substrate, the molecules selectively adsorb and form a well defined two-dimensional grid with 1x1 surface patterns.
Graphene and porous graphene are very promising materials, which have been widely studied for electronic applications. It was expected, that graphene, porous graphene and graphene-like molecules will effectively replace silicon. Despite it superior properties relative to traditional materials, however, the field-effect transistors based on graphene or graphene nanoribbons build so far via top-down approaches have low on/off ratios. On the other hand, molecular nanotransistors build with precisely know atomic structures resembling graphene were synthesized only very recently. In order to pave the way towards the industrial fabrication of molecular nanotransistors, we have investigated the chemisorption of graphene-like molecules on the 7x7 reconstructed Si(111) surface via large-scale density functional theory (DFT) calculations including van-der-Waals corrections. We found, that Si(111) is a very promising candidate to serve as a substrate for the deposition of coronene-based molecular transistors. Moreover, our results show, that various adsorbate molecules prefer specific binding sites on the Si(111) surface, and van-der-Waals forces considerably change the energetics. By following the template of the Si(111) substrate, the molecules selectively adsorb and form a well defined two-dimensional grid with 1x1 surface patterns.
