THz spectroscopy of graphene-like materials compounds and hybrids for the developments of bio-compatible devices

Organic electronics is a promising field for investigating a series of materials offering relevant advantages with respect to traditional electronics as the possibility to create bendable circuits compatible with human biology. Graphene for its electrical properties (and abundance) represents the desirable compound to trigger a strong development of bioelectronics although its properties are strongly affected by topology, defects and external contamination [1]. This problem can affect the reproducibility and yield of the production of bioelectronics devices. The issue can be circumvented by the use of graphene-like (GL) layers, a graphene related materials (GRM) which are composed of stacks of few graphene layers [2] having micrometer size on average. The loss of the pure two dimensional conduction is compensated by a lower reactivity with a higher versatility due to the initial stable liquid phase of the GL suspensions[2,3]. In the THz region, graphene and GL compounds have attracted much interest as promising candidates for photosensitive and optoelectronic devices. At very high frequencies, however, transport and quantum efficiency in multi-layer graphene structures can be strongly influenced by particle size and stacking configuration. In this contribution we present THz time-domain spectroscopy of GL and GL hybrids obtained by drop casting on silicon dioxide substrates. We provide the electrodynamic characterization of both pure and eumelanin-GL hybrids [4], which are valuable materials for the next generation of bio-devices.