Transconductance and Coulomb blockade properties of in-plane grown carbon nanotube field effect transistors (original) (raw)
Related papers
Single- and multi-wall carbon nanotube field-effect transistors
Applied Physics Letters, 1998
We fabricated field-effect transistors based on individual single-and multi-wall carbon nanotubes and analyzed their performance. Transport through the nanotubes is dominated by holes and, at room temperature, it appears to be diffusive rather than ballistic. By varying the gate voltage, we successfully modulated the conductance of a single-wall device by more than 5 orders of magnitude. Multi-wall nanotubes show typically no gate effect, but structural deformations-in our case a collapsed tube-can make them operate as field-effect transistors. © 1998 American Institute of Physics. ͓S0003-6951͑98͒00143-0͔
Advances and Frontiers in Single-Walled Carbon Nanotube Electronics
Single-walled carbon nanotubes (SWCNTs) have been considered as one of the most promising electronic materials for the next-generation electronics in the more Moore era. Sub-10 nm SWCNT-field effect transistors (FETs) have been realized with several performances exceeding those of Si-based FETs at the same feature size. Several industrial initiatives have attempted to implement SWCNT electronics in integrated circuit (IC) chips. Here, the recent advances in SWCNT electronics are reviewed from in-depth understanding of the fundamental electronic structures, the carrier transport mechanisms, and the metal/SWCNT contact properties. In particular, the subthreshold switching properties are highlighted for low-power, energy-efficient device operations. State-of-the-art low-power SWCNT-based electronics and the key strategies to realize low-voltage and low-power operations are outlined. Finally, the essential challenges and prospects from the material preparation, device fabrication, and large-scale ICs integration for future SWCNT-based electronics are foregrounded.
Single-electron transistor made of multiwalled carbon nanotube using scanning probe manipulation
Applied Physics Letters, 1999
We positioned semiconducting multiwalled carbon nanotube, using an atomic force microscope, between two gold electrodes at SiO 2 surface. Transport measurements exhibit single-electron effects with a charging energy of 24 K. Using the Coulomb staircase model, the capacitances and resistances between the tube and the electrodes can be characterized in detail. © 1999 American Institute of Physics. ͓S0003-6951͑99͒00131-X͔ Carbon nanotubes 1 represent a new building block for nanotechnology and nanoelectronics. They may be considered as graphite sheets wrapped into seamless cylinders. The two types of nanotubes are multiwalled carbon nanotube ͑MWNT͒, where many tubes are arranged in a coaxial fashion, and a single-walled nanotube ͑SWNT͒, consisting of only a single layer. The tubes are either metallic, semimetallic or semiconducting depending on how the graphite sheets are wrapped around. The electrical properties of the carbon nanotubes have been exploited, e.g., in single-electron transistor ͑SET͒ made of ropes of SWNTs 3 and in a room temperature transistor made of SWNT. 4 There are also investigations on the resistance of a nanotube/metal-contact system, 5 and on soldering a low-ohmic contact using an electron beam. Since the early work by Junno et al., 7 scanning probe microscopes ͑SPM͒ have been utilized for manipulation of small metal particles. 8,9 Also MWNTs have been moved using SPM 10 and they have been a subject in tribological studies of sliding and rolling friction between the nanotube and the substrate. 11 In this letter, we report a MWNT single electronics device fabricated using scanning probe manipulation. This may be considered as a new fabrication method towards molecular electronics.
Substrate-induced array of quantum dots in a single-walled carbon nanotube
Nature Nanotechnology, 2009
Single-walled carbon nanotubes are model one-dimensional structures 1-6 . They can also be made into zero-dimensional structures; quantum wells can be created in nanotubes by inserting metallofullerenes 7 , by mechanical cutting 8-10 or by the application of mechanical strain 11 . Here, we report that quantum dot arrays can be produced inside nanotubes simply by causing a misalignment between the nanotube and the k100l direction of a supporting silver substrate. This method does not require chemical or physical treatment of either the substrate or the nanotube. A short quantum dot confinement length of 6 nm results in large energy splittings.
Nano Letters, 2004
To take advantage of nanoscale molecular electronic components in semiconductor technology, there will be a desire to integrate new elements such as one-dimensional (1D) carbon nanotubes in conventional 2D or 3D semiconductor systems. We report on hybrid devices based on single wall carbon nanotubes encapsulated in epitaxially grown semiconductor heterostructures of GaAs/AlAs and (Ga,Mn)As below and above the carbon nanotube. In our devices the semiconductor serves as leads to the nanotubes, forming the first reported electronic hybrid nanotube-semiconductor devices.
Molecular doping of single-walled carbon nanotube transistors: optoelectronic study
Single-walled carbon nanotubes (SWCNT) are a promising material for future optoelectronic applications, including flexible electrodes and field-effect transistors. Molecular doping of carbon nanotube surface can be an effective way to control the electronic structure and charge dynamics of these material systems. Herein, two organic semiconductors with different energy level alignment in respect to SWCNT are used to dope the channel of the SWCNT-based transistor. The effects of doping on the device performance are studied with a set of optoelectronic measurements. For the studied system, we observed an opposite change in photo-resistance, depending on the type (electron donor vs electron acceptor) of the dopants. We attribute this effect to interplay between two effects: (i) the change in the carrier concentration and (ii) the formation of trapping states at the SWCNT surface. We also observed a modest ~4 pA photocurrent generation in the doped systems, which indicates that the studied system could be used as a platform for multi-pulse optoelectronic experiments with photocurrent detection.
IEEE Transactions on Nanotechnology, 2002
Presents experimental results on single-wall carbon nanotube field-effect transistors (CNFETs) operating at gate and drain voltages below 1V. Taking into account the extremely small diameter of the semiconducting tubes used as active components, electrical characteristics are comparable with state-of-the-art metal oxide semiconductor field-effect transistors (MOSFETs). While output as well as subthreshold characteristics resemble those of conventional MOSFETs, we find that CNFET operation is actually controlled by Schottky barriers (SBs) in the source and drain region instead of by the nanotube itself. Due to the small size of the contact region between the electrode and the nanotube, these barriers can be extremely thin, enabling good performance of SB-CNFETs.
Schottky Barriers and Coulomb Blockade in Self-Assembled Carbon Nanotube FETs
Nano Letters, 2003
We report low-temperature electronic transport in batch-processed single-walled carbon nanotube (SWNT) field-effect transistors (FETs). SWNTs are in situ synthesized and wired between submicrometer metallic electrodes in a single-step process involving hot-filament-assisted chemical vapor deposition. FETs show a pronounced ambipolar field effect between 1 and 300 K. Moreover, the gate dependence exhibits hysteresis at any temperature because of the extraction and trapping of charges. We find Schottky barriers at the SWNT/metal contact to be responsible for the field effect. Below 30 K, potential barriers along the SWNT induce a Coulomb blockade at low drain-source bias, leading to the suppression of the field-effect gain and inducing fluctuations in the transconductance.
Physics of carbon nanotube electronic devices
Reports on Progress in Physics, 2006
Carbon nanotubes (CNTs) are amongst the most explored one-dimensional nanostructures and have attracted tremendous interest from fundamental science and technological perspectives. Albeit topologically simple, they exhibit a rich variety of intriguing electronic properties, such as metallic and semiconducting behaviour. Furthermore, these structures are atomically precise, meaning that each carbon atom is still three-fold coordinated without any dangling bonds. CNTs have been used in many laboratories to build prototype nanodevices. These devices include metallic wires, field-effect transistors, electromechanical sensors and displays. They potentially form the basis of future all-carbon electronics. This review deals with the building blocks of understanding the device physics of CNT-based nanodevices. There are many features that make CNTs different from traditional materials, including chirality-dependent electronic properties, the one-dimensional nature of electrostatic screening and the presence of several direct bandgaps. Understanding these novel properties and their impact on devices is crucial in the development and evolution of CNT applications.