In the present chapter a variety of different electrically connected low density and high density multi-walled carbon nanotube networks will be presented, which have in common the use of the same type of multi-walled carbon nanotubes. In a first step the interconnection between single nanotubes has been investigated by means of SEM imaging and a shoestring-knot type connection has been found in the case of low-density CNT networks deposited on top of thermally oxidized silicon, that have been successively contacted by focused ion beam deposition of platinum contacts. In a second step, electrical contacts in a micro-gap configuration have been deposited first on the thermally oxidized silicon wafer and this micro-gap has been successively bridged by a high-density carbon nanotube network, deposited using the di-electrophoresis technique. In this case - after an initial burn-in procedure - a stable and at room-temperature linear current-voltage characteristics with a negative temperature coefficient of the resistance has been obtained. The measured temperature-dependence of the resistance is dominated by the interconnection resistance between the single nanotubes within a percolation path. Subsequently we investigated three different types of heterojunctions between crystalline silicon as base layers and spin-coating deposited organic thin film emitters with and without incorporated carbon nanotubes. In a first case the realization of inorganic/organic heterojunction solar cells with semiconducting PEDOT:PSS emitters has been demonstrated. Then we demonstrated, how a heterojunction between crystalline silicon and an oxadiazole based electron conducting polymer enables to produce a very simple electronic memory with reproducible bistabilities for applied bias voltages below 0.6 V and finally we compared the diode properties of heterodiodes, where the organic emitter layer is formed by the multi-walled carbon nanotubes embedded into an isolating PMMA matrix. The Schottky type character of these type of heterodiodes becomes more and more pronounced, when the nanotube concentration in the PMMA layer increases. In a last set of experiments, we used the CNT networks in order to produce a strongly conducting tissue with fungal cells. The CNT’s have been added in vivo to the fungal cells and enabled them to form a mechanically stable tissue. The resulting bio-nanocomposite has been found to be stable even at elevated temperatures and in a the range between room temperature and 100°C a linear increase of the conductivity with increasing temperature has been found with a temperature coefficient similar to that of the CNT network, deposited by di-electrophoresis into a micro-gap between aluminum contacts, as reported before.

Multi-walled Carbon Nanotube Network-based Sensors and Electronic Devices

LANDI, GIOVANNI;DI GIACOMO, RAFFAELE;NEITZERT, Heinrich Christoph;
2015

Abstract

In the present chapter a variety of different electrically connected low density and high density multi-walled carbon nanotube networks will be presented, which have in common the use of the same type of multi-walled carbon nanotubes. In a first step the interconnection between single nanotubes has been investigated by means of SEM imaging and a shoestring-knot type connection has been found in the case of low-density CNT networks deposited on top of thermally oxidized silicon, that have been successively contacted by focused ion beam deposition of platinum contacts. In a second step, electrical contacts in a micro-gap configuration have been deposited first on the thermally oxidized silicon wafer and this micro-gap has been successively bridged by a high-density carbon nanotube network, deposited using the di-electrophoresis technique. In this case - after an initial burn-in procedure - a stable and at room-temperature linear current-voltage characteristics with a negative temperature coefficient of the resistance has been obtained. The measured temperature-dependence of the resistance is dominated by the interconnection resistance between the single nanotubes within a percolation path. Subsequently we investigated three different types of heterojunctions between crystalline silicon as base layers and spin-coating deposited organic thin film emitters with and without incorporated carbon nanotubes. In a first case the realization of inorganic/organic heterojunction solar cells with semiconducting PEDOT:PSS emitters has been demonstrated. Then we demonstrated, how a heterojunction between crystalline silicon and an oxadiazole based electron conducting polymer enables to produce a very simple electronic memory with reproducible bistabilities for applied bias voltages below 0.6 V and finally we compared the diode properties of heterodiodes, where the organic emitter layer is formed by the multi-walled carbon nanotubes embedded into an isolating PMMA matrix. The Schottky type character of these type of heterodiodes becomes more and more pronounced, when the nanotube concentration in the PMMA layer increases. In a last set of experiments, we used the CNT networks in order to produce a strongly conducting tissue with fungal cells. The CNT’s have been added in vivo to the fungal cells and enabled them to form a mechanically stable tissue. The resulting bio-nanocomposite has been found to be stable even at elevated temperatures and in a the range between room temperature and 100°C a linear increase of the conductivity with increasing temperature has been found with a temperature coefficient similar to that of the CNT network, deposited by di-electrophoresis into a micro-gap between aluminum contacts, as reported before.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11386/4653111
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 2
  • ???jsp.display-item.citation.isi??? ND
social impact