Search results for "field-effect"
showing 10 items of 61 documents
Noncovalent Functionalization and Passivation of Black Phosphorus with Optimized Perylene Diimides for Hybrid Field Effect Transistors
2020
Amongst the different existing methods to passivate black phosphorus (BP) from environmental degradation, the noncovalent functionalization with perylene diimides (PDI) has been postulated as one of the most promising routes because it allows preserving its electronic properties. This work describes the noncovalent functionalization and outstanding environmental protection of BP with tailor made PDI having peri-amide aromatic side chains, which include phenyl and naphthyl groups, exhibiting a significantly increased molecule-BP interaction. These results are rationalized by density functional theory (DFT) calculations showing that the adsorption energies are mainly governed by van der Waals…
Surface plasmon effects on carbon nanotube field effect transistors
2011
Herein, we experimentally demonstrate surface plasmon polariton (SPP) induced changes in the conductivity of a carbon nanotube field effect transistor (CNT FET). SPP excitation is done via Kretschmann configuration while the measured CNT FET is situated on the opposite side of the metal layer away from the laser, but within reach of the launched SPPs. We observe a shift of 0.4 V in effective gate voltage. SPP-intermediated desorption of physisorbed oxygen from the device is discussed as a likely explanation of the observed effect. This effect is visible even at low SPP intensities and within a near-infrared range. peerReviewed
Nanocrystal metal-oxide-semiconductor memories obtained by chemical vapor deposition of Si nanocrystals
2002
We have realized nanocrystal memories by using silicon quantum dots embedded in silicon dioxide. The Si dots with the size of few nanometers have been obtained by chemical vapor deposition on very thin tunnel oxides and subsequently coated with a deposited SiO2 control dielectric. A range of temperatures in which we can adequately control a nucleation process, that gives rise to nanocrystal densities of ∼3×1011 cm−2 with good uniformity on the wafer, has been defined. The memory effects are observed in metal-oxide-semiconductor capacitors or field effect transistors by significant and reversible flat band or threshold voltage shifts between written and erased states that can be achieved by …
Efficiency comparison between SiC- and Si-based active neutral-point clamped converters
2015
This paper presents an efficiency comparison between silicon-carbide technology and silicon technology. In order to achieve this, the efficiency of an active neutral-point clamped converter built up with silicon carbide power-devices is compared with the efficiency of an active neutral-point clamped converter built up with silicon power-devices, under a particular operating mode and a particular selection of devices. Firstly, overall losses of both converters are estimated. Then, experimental tests are carried out to measure their overall losses and efficiency. Finally, experimental results are compared with the estimations to support the analysis. The efficiency of the SiC converter is hig…
Supramolecular Order of Solution-Processed Perylenediimide Thin Films
2011
N,N ′ -1 H ,1 H -perfl uorobutyl dicyanoperylenecarboxydiimide (PDIF-CN 2 ), a soluble and air stable n-type molecule, undergoes signifi cant reorganization upon thermal annealing after solution deposition on several substrates with different surface energies. Interestingly, this system exhibits an exceptional edge-on orientation regardless of the substrate chemistry. This preferential orientation is rationalized in terms of strong intermolecular interactions between the PDIF-CN 2 molecules. The presence of a pronounced π– π stacking is confi rmed by combining near-edge X-ray absorption fi ne structure spectroscopy (NEXAFS), dynamic scanning force microscopy (SFM) and surface energy measure…
High-Speed Memory from Carbon Nanotube Field-Effect Transistors with High-κ Gate Dielectric
2009
We demonstrate 100 ns write/erase speed of single-walled carbon nanotube field-effect transistor (SWCNT-FET) memory elements. With this high operation speed, SWCNT-FET memory elements can compete with state of the art commercial Flash memories in this figure of merit. The endurance of the memory elements is shown to exceed 104 cycles. The SWCNT-FETs have atomic layer deposited hafnium oxide as a gate dielectric, and the devices are passivated by another hafnium oxide layer in order to reduce surface chemistry effects. We discuss a model where the hafnium oxide has defect states situated above, but close in energy to, the band gap of the SWCNT. The fast and efficient charging and discharging…
Effect of humidity on the hysteresis of single walled carbon nanotube field-effect transistors
2008
Single walled carbon nanotube field-effedt transistores (SWCNT FETs) are attributed as possible building blocks for future molecular electronics. But often these transistors seem to randomly display hysteresis in their transfer characteristics. One reason for this is suggested to be water molecules adsorbed to the surface of the gate dielectric in this study we investigate the thysteresis of SWCNT FETs at different relative humidities. We find that SWCNT FETs having atomic layer deposited (ALD) Hf0 2 -Ti0 2 .- Hf0 2 as a gate dielectric retain their. ambient condition hysteresis better in dry N2 environment than the more commonly used SiO 2 gate oxide.
Electrical excitation of surface plasmons by an individual carbon nanotube transistor.
2013
We demonstrate here the realization of an integrated, electrically driven, source of surface plasmon polaritons. Light-emitting individual single-walled carbon nanotube field effect transistors were fabricated in a plasmonic-ready platform. The devices were operated at ambient conditions to act as an electroluminescence source localized near the contacting gold electrodes. We show that photon emission from the semiconducting channel can couple to propagating surface plasmons developing in the electrical terminals. Our results show that a common functional element can be operated for two different platforms emphasizing thus the high degree of compatibility between state-of-the-art nano-optoe…
Carbon Nanotube Radio-Frequency Single-Electron Transistor
2004
We discuss the theory of the radio-frequency single-electron transistor and the measurements that use multiwalled carbon nanotubes as active elements. Our devices made of plasma-enhanced chemical-vapor-deposition nanotubes yield charge sensitivities of 10-20 μe/ $$\sqrt {Hz}$$ . PACS numbers: 73.23.Hk, 73.63.Fg, 85.35.Gv, 85.35.Kt.
Impact of contact resistance on the electrical properties of MoS2 transistors at practical operating temperatures
2017
Molybdenum disulphide (MoS2) is currently regarded as a promising material for the next generation of electronic and optoelectronic devices. However, several issues need to be addressed to fully exploit its potential for field effect transistor (FET) applications. In this context, the contact resistance, RC, associated with the Schottky barrier between source/drain metals and MoS2 currently represents one of the main limiting factors for suitable device performance. Furthermore, to gain a deeper understanding of MoS2 FETs under practical operating conditions, it is necessary to investigate the temperature dependence of the main electrical parameters, such as the field effect mobility (μ) an…