Seminar by Dr Romagnoli, 'Graphene on Transparent Dielectric Substrates for Photonics Applications'

Speaker:
Priscila Romagnoli, Ph.D.

Seminar Title:
Graphene on Transparent Dielectric Substrates for Photonics Applications

Abstract:
A study of graphene on transparent dielectric substrates for photonic applications will be presented. The study has two main objectives: first, to develop techniques to enhance the optical contrast of graphene on transparent substrates; and second, to investigate a new electric doping technique for graphene on silicate glasses. Graphene has low values of optical contrast on transparent substrates. Usually, an interferometric layer is used to enhance the contrast. For photonic applications, graphene properties can be modified by the interferometric layer. One of the techniques developed consists of imaging at the Brewster angle incidence of the dielectric substrate, in which it was demonstrated to highly increase the optical contrast. Furthermore, it is essential to control the optical properties of graphene to enable the production of optimized and active photonics devices. Doping processes allow tuning graphene optical properties, and it is usually obtained by the application of electrical voltage. Here, a new electric doping technique for graphene was presented and characterized, based on the thermal poling of silicate glasses. Therefore, an electric field is recorded onto the substrate and graphene is doped without an external active source.