Carbon nanotubes: Synthesis, Characterization and Integration
Date | Do, 24.11.2011 | |
Time | 10.15 | |
Speaker | Dr. Salvatore Bagiante, Laboratory for Micro- and Nanotechnology, PSI, Villigen | |
Location | Universität Bern, Institut für Angewandte Physik, Gebäude exakte Wissenschaften, Hörsaal B77, Sidlerstrasse 5, 3012 Bern | |
Program | Since the 1950s, the semiconductor industry has been able to improve the performance of electronic systems for more than four decades by making ever smaller devices. However, this approach will soon encounter both scientific and technical limits, which is why the industry is exploring a number of alternative device technologies. In this context, particular emphasis has been placed on research of carbon materials. Carbon nanotubes (CNTs) and graphene have been among the most promising candidate for the next generation electronics. The first part of this work is focused on the study of CNTs synthesis by one of the techniques that allow high yield/cost ratio: arc discharge in liquid nitrogen. This method still needs to be fully understood in order to achieve a good control of the produced nanomaterials and their properties by the use of suitable experimental parameters. We report a morphological study of the Carbon deposit produced and study the effect of the size of electrodes, applied voltage and discharge current on the formation of Multi Wall CNTs and hybrid structure (linear carbon chains (LCCs) and CNTs). The second aspect that has been considered in this work is the use of Single Wall CNTs for the fabrication of new and innovative devices. The unconventional approach considered here is the use of ultra-clean nanotubes, grown by chemical vapor deposition in the very last fabrication step, after all the device structure has already been completed. We report a description of the fabrication process of an optoelectronic device based on ultra-clean carbon nanotubes. After that, we present the preliminary results obtained by electrical and optical characterization. Optical measurements, realized by means of the Scanning photocurrent microscopy (SPCM) technique, permit to investigate the spatial variations of the potential along the suspended nanotubes for different gates voltages under laser excitation without altering its characteristics. In our case, SPCM allow us to observe how a precise doping spatial control in the nanotube can be achieved in this kind of device. G. Buchs, S. Bagiante et al., Journal of Applied Physics in press (2011). Scuderi, S. Bagiante et al., CARBON 47, 2112–2142 (2009). S. Scalese, S. Bagiante et al., Journal of applied physics, 107, 014304 (2010) S. Bagiante, S. Scalese et al., Physics Status Solid B 247, No. 4, 884–887 (2010). |
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Link | www.iap.unibe.ch |