Photonics and Optoelectronics
Optoelectronics – Roman Krahne’s group
Graphene is bound to become the material of choice for engineering environmentally friendly devices including neuroprostheses. However, the small size and unique properties of graphene pose potential risks to human health. Nanosafety is crucial to translate any future development of graphene into action, especially for bio-medical applications.
Our research activities want to address the following questions:
- How can the plasmon propagation in graphene wave guides be increased to practical length scales?
- How can electrical generation of graphene plasmons be achieved?
- Can the unique properties of graphene be exploited laser devices or light emitting diodes based on other emitter materials?
- Ultrasensitive nanocrystal sensitized graphene photodetectors working in the UV spectral range at kHz frequencies
- Methods for on-chip launching of plasmon via planar metal antennas
- Pathways for the shape and design of plasmonic waveguides in graphene that promise strongly enhanced plasmon propagation
Research activities are conducted in the following research lines:
- Hybrid nanocrystal-graphene systems for photodetection
- High mobility graphene layers fabricated by chemical vapor deposition (CVD) and encapsulation
- Design and fabrication of plasmonic structures and waveguides in graphene
Connection with Graphene Flagship project
- Task 8.1 Photodetectors for visible, near-IR and shortwave IR
- Task 8.5 Tuneable plasmonic materials and metamaterials for modulation, sensing and photodetection
- Task 4.6 Exploiting the conductive properties of graphene in 2D neuronal interfaces and studying the physiology of neuronal cells and biological barriers challenged with GRMs
Photodetector based on a graphene field effect transistor that is sensitized with a layer of colloidal semiconductor nanocrystals. Such devices allow for ultrasensitive and fast photodetection in a spectral range that can be tuned by the nanocrystal properties.
Plasmon excitation in a tapered graphene waveguide by a metallic dipole antenna that is illuminated with infrared light.