(581g) η6 Chemical Modification of Epitaxial Graphene: A New Chemical Route for Atomic Layer Deposition and Fabricating Ultrasensitive Biological Sensors

In this talk, we will demonstrate a novel route to modify the surface of pristine graphene via η6 bond formation with metal carbonyls that utilizes the π-electrons derived from the conjugated graphene structure for filling the vacant metal orbitals resulting in a unique grafting of metal atoms on the center of graphene aromatic rings. Such an aromatic binding of metal atom on graphene is expected to minimally interfere with the structural integrity of the sp2 hybridized carbon atoms, a factor which is central to retaining the superior properties of graphene (high density of π electrons and their relatively un-scattered motion). We utilize, (a) the carbonyl groups on the η6 modified graphene for facilitating an interface with biological molecules to fabricate graphene based ultra-sensitive electro-chemical transistor for enhanced biomolecular recognition, and (b) the self-limiting nature of η6 functionalization to achieve a single atom thick HfO2 film on graphene surface for semiconducting applications. The η6 modified graphene is characterized in detail for its electronic properties (nature, band-gap, density and mobility of charge carriers) and the process parameter factors that govern the modulation of these properties. This non-invasive metal functionalization scheme holds enormous potential to enable a controlled graphene manipulation and incorporation into advanced semiconducting applications (fabrication of FETs, sensors and gated devices)