Speaker: Prof. Stefan Strauf, Stevens Institute of Technology

Title:  Grapheotonics: Photonics with CNTs and Graphene

Abstract:

Carbon allotropes such as carbon nanotubes (CNTs) and graphene are well known for their outstanding electronic, thermal, and mechanical properties and have recently also gained tremendous interest as a nanomaterial for photonics and quantum photonics devices. In this talk we will review some of our recent work: Blinking and spectral diffusion are hallmarks of nanoscale light emitters. We demonstrate suppression of blinking in individual CNTs by manipulation of their dielectric environment, resulting in five-fold enhanced exciton emission. For exfoliated graphene we show how Raman spectroscopy can be used for layer metrology and to determine the fractional composition of armchair and zigzag edges. We furthermore show that aperiodic conductivity oscillations in dual-gated graphene field-effect transistors can be understood as a signature of Klein-tunneling. Finally, we will present recent results on photocurrent measurements of large-scale graphene grown by CVD and transferred onto flexible substrates leading to IR detectors with strain-tunable bandgaps.