Manufacturing Transparent Conducting Films Based on Directly Exfoliated Graphene Particles via Langmuir–Blodgett Technique

Resumo

Transparent conducting films based on graphene particles are obtained via ultrasonic-assisted liquid-phase exfoliation of natural graphite. For the first time, the Langmuir–Blodgett technique is reported to be utilized for the deposition of transparent conducting thin films based on directly exfoliated graphene on dielectric substrates (glass and lithium niobate). It is shown that centrifugation of graphene suspensions prior to the film deposition enables the formation of conducting coatings with high transparency (higher than 90%). A number of film parameters (sheet conductance, transmission coefficient in the optical domain) are investigated; the achieved level of properties (the sheet resistance of 143 Ω/sq at the optical transmission coefficient of 90% and the weak dependence of absorption on the wavelength) makes these films an attractive material for transparent electrodes in photovoltaic devices, light emitting diodes, and advanced sensor technologies. The samples of graphene-based films deposited on a transparent piezoelectric substrate (lithium niobate) showed themselves as candidates for application as a part of primary transducers for electronic devices and sensing technologies as a possible substitute for ceramic materials based on indium-tin oxide.