Reversible fluorination of graphene: Evidence of a two-dimensional wide bandgap semiconductor

Abstract

We report the synthesis and evidence of graphene fluoride, a two-dimensional wide bandgap semiconductor derived from graphene. Graphene fluoride exhibits hexagonal crystalline order and strongly insulating behavior with resistance exceeding 10 GΩ at room temperature. Electron transport in graphene fluoride is well described by variable-range hopping in two dimensions due to the presence of localized states in the band gap. Graphene obtained through the reduction of graphene fluoride is highly conductive, exhibiting a resistivity of less than 100 kΩ at room temperature. Our approach provides a new path to reversibly engineer the band structure and conductivity of graphene for electronic and optical applications.

Atomically resolved imaging of highly ordered alternating fluorinated graphene

“…This material is a thermally and chemically stable insulator with similar mechanical strength to graphene, offering a range of possible applications [8][9][10][11][12][13] . However the reported two-dimensional (2D) lattice constant for CF is B0.248 nm, which is apparently expanded only 1% relative to graphene, significantly lower than the 2.8% expanded lattice constant for monolayer CF predicted by the density functional theory (DFT) and notably also less than the 2.8-4.5% expanded lattice constant variously reported for graphite fluoride 8,10,14,15 .…”

Structural, mechanical, and electronic properties of defect-patterned graphene nanomeshes from first principles

“…The C 4 defective GNM shows metallic behavior. The situation becomes even more remarkable for larger defects: C 6 , C 12 , and C 24 . GNMs including either a C 6 or a C 24 hole have zigzag edges and are metals with an antiferromagnetic ground state.…”

“…So far three known derivatives of graphene have been successfully achieved in chemical reactions: graphene oxide (GO), [15][16][17][18] graphane (CH), [19][20][21][22] and, recently, fluorographene (CF). [23][24][25] Although GO is a wideband-gap material that is important for device applications, its atomic structure, wherein the carbon atoms are decorated with epoxides, alcohols, and carboxylic acid groups, is not suitable for nanoscale manipulations. CH, obtained by exposing a carbon honeycomb structure to hydrogen plasma, is another example of a graphene-based chemical derivative.…”

Bandgap formation in graphene on Ir(111) through oxidation

“…And yet, to fully harness the power of graphene, the ideal conduction properties of graphene need to be disturbed in order to obtain a (tunable) band gap and thereby achieve semiconducting behaviour. One way is to attach (covalently) bound species, such as H, O or F to the surface of graphene [3,4,5]. This is also known from graphene oxide (GO), which is an insulator accommodating several oxygen species (e.g., C=O, C-O-C, COOH, OH) on both the basal planes and the edges of flakes as it is often prepared chemically, ex-situ [6,7].…”