Dresden 2011 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 91: Joint Focussed Session: Theory and Computation of Electronic Structure: New Frontiers VIII

HL 91.1: Topical Talk

Friday, March 18, 2011, 11:15–11:45, TRE Phy

Tunable bandgaps and excitons in doped semiconducting carbon nanotubes made possible by acoustic plasmons — •Catalin Spataru and Francois Leonard — Sandia National Laboratories, Livermore, California, USA

Doping of semiconductors is essential in modern electronic and photonic devices. While doping is well understood in bulk semiconductors, the advent of carbon nanotubes and nanowires for nanoelectronic and nanophotonic applications raises some key questions about the role and impact of doping at low dimensionality. Here we show that for semiconducting carbon nanotubes, bandgaps and exciton binding energies can be dramatically reduced upon experimentally relevant doping, and can be tuned gradually over a broad range of energies in contrast to higher dimensional systems. The later feature, made possible by a novel mechanism involving acoustic plasmons, establishes new paradigms for the understanding and design of nanoelectronic and nanophotonic devices.