Fluorinated Graphene Dielectric and Functional Layers for Electronic Applications

Abstract

Future electronics technology is expected to develop from rigid to flexible devices. This process requires breakthroughs in material properties, especially flexibility, in combination with desirable electrical insulating, semiconducting, or metallic properties. Graphene, being one of the recently developed two-dimensional (2D) materials, presents great promise as an active layer in a wide spectrum of electronics devices and, first of all, in field-effect transistors (FET). The development of optimized dielectrics for the graphene active layer is critical for graphene applications. The carrier transport in graphene films takes place at interfaces with dielectric or semiconductor substrates; therefore, the quality of such interface and the interaction of graphene films with nearby dielectric layers (charge carrier scattering) determine the device performance. Generally, the development of dielectric materials aiming at high performance device operation, proper mechanical properties, and low-temperature fabrication is not progressing well since the graphene thin film is very sensitive to surface conditions of dielectric layers. Solving the problem with dielectric layers in the case of nonorganic printed and flexible electronics is especially acute. As it is demonstrated in the present chapter, dielectric layers fabricated from fluorinated graphene suspension or in its combination with graphene oxide are the most promising for graphene-based flexible, printed, and transparent electronics.

Electrochemical Exfoliation of Graphite to Fluorographene: An Effect of Degree of Functionalization on 2Br−/Br2 Redox Reaction

“…[23][24][25] Moreover, FG is one of the most useful materials in diverse applications ranging from biological, [26,27] energy harvesting [28] and storage, [2,28] sensing, [29] to electronic applications. [30,31] Electrochemical properties of the fluorinated graphene sheets can also be tuned by varying the fluorine content attached to the graphene sheet. For instance, Praveen Meduri et al [2] have synthesized FG with different degree of fluorination (CF x where x = 0.47, 0.66 and 0.89) and studied their electrochemical properties by using them as anode material in primary lithium batteries.…”

Graphene/Fluorinated Graphene Systems for a Wide Spectrum of Electronics Application

“…The thickness of the printed films was 20-40 nm. Capacitance-voltage measurements performed on such structures have shown that the dielectric films printed out from FG suspensions demonstrated an ultra-low built-in charge of (0.5-4) × 10 10 cm -2 and a roughly identical density of states at the hetero-boundary with semiconductors [11]. In those cases in which the dielectric films in MIS structures were obtained by printing, the magnitude of the builtin charges approached the lower boundary of the indicated range.…”

“…The main process steps in the fabrication of grapheme-and fluoro-graphene-based structures Recently, we have developed a graphene fluorination process which permits the preparation of materials with unique electrical (from conductors to insulators, depending on the fluorination degree) and optical properties [9][10][11]. The method is based on processing graphene or few layer graphene in an aqueous solution of hydrofluoric acid.…”