ERA NanoSci - Electrically-Excited Surface Plasmon Nanosources Based on Carbon Nanotube Light Emission
Final Report Abstract
Carbon nanotube optoelectronics and plasmonics exploit novel fascinating physical phenomena and are among the most promising research areas for nanotechnology providing functional nano-objects for data transfer and processing at ultimate device densities. With E²-Plas, we proposed to interface these two technologies to create an electrically-driven surface plasmon source. The research work was carried out in collaboration with the groups of Dr. Bouhelier and Prof. Allegrini in the framework of the NanoSci-E+ Transnational Call for Collaborative Proposals (2008). E²-Plas focused on the design, fabrication, characterization and optimization of an electrically-driven surface plasmon generator utilizing electroluminescent single-walled carbon nanotubes (SWCNTs). In the first work package we investigated the possibility of remote optical excitation of single-walled carbon nanotubes by propagating surface plasmons polaritons (SPPs). Using SPPs launched either in the Kretschmann configuration or by a raster-scanning an aperture probe as near-field source we were able to observe the optical excitation of single SWCNTs by detecting their photoluminescence (PL) signal. These experiments also allowed us to the study coupling between SPPs and the exciton states in single SWCNTs. The second work package focused on the reversed process, namely the excitation of surface plasmons using optically excited SWCNTs. In the first configuration the SWCNTs were used to excite plasmons in a sharp gold tip that is also used in near-field microscopy. Using back-focal plane imaging we showed that the metal tip acts as an optical antenna by enhancing the radiative relaxation rate of the nanotubes and by spatially redistributing their emission. In the second configuration we deposited SWCNTs on top of a thin metal film and demonstrated the launching of propagating surface plasmon polaritons via single excited SWCNTs. For both configurations we succeeded in modeling the samples response quantitatively. In the final work package we fabricated SWCNT field effect transistors using electrode materials suitable for plasmonic applications. We successfully realized electrically-driven surface plasmon sources in which SPPs were launched either directly in the electrodes or in an additional stripe waveguide. In summary, all work packages led to significant new findings and finally resulted in the fabrication of the envisioned novel device. This was made possible by the very efficient collaboration between the three participating groups and the combination and exchange of their complementary expertise. As an additional result, this project contributed substantially to the development of new scientific knowledge and experimental skills in my group, mainly in the fields of plasmonics and SPP detection and provided the platform for several new studies.
Publications
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"Enhancing and Redirecting Carbon Nanotube Photoluminescence by an Optical Antenna", Optics Express 18, 16443 (2010)
M. Böhmler, N. Hartmann, C. Georgi, F. Hennrich, M.C. Hersam and A. Hartschuh
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"In-plane remote photoluminescence excitation of carbon nanotube by propagating surface plasmon", Optics Letters 37, 4711 (2012)
. P. Rai, N. Hartmann, J. Berthelot, G. Colas-des-Francs, A. Hartschuh and A. Bouhelier
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"Launching Propagating Surface Plasmon Polaritons by a Single Carbon Nanotube Dipolar Emitter", Nano Letters 12, 177 (2012)
N. Hartmann, G. Piredda, J. Berthelot, G. Colas des Francs, A. Bouhelier and A. Hartschuh
