Field effect

About: Field effect is a research topic. Over the lifetime, 4018 publications have been published within this topic receiving 92613 citations.

Semiconductor devices with non-punch-through semiconductor channels having enhanced conduction and methods of making

Abstract: Semiconductor devices are described wherein current flow in the device is confined between the rectifying junctions (e.g., p-n junctions or metal-semiconductor junctions). The device provides non-punch-through behavior and enhanced current conduction capability. The devices can be power semiconductor devices as such as Junction Field-Effect Transistors (VJFETs), Static Induction Transistors (SITs), Junction Field Effect Thyristors, or JFET current limiters. The devices can be made in wide bandgap semiconductors such as silicon carbide (SiC). According to some embodiments, the device can be a normally-off SiC vertical junction field effect transistor. Methods of making the devices and circuits comprising the devices are also described.

Magnetically induced field effect in carbon nanotube devices

Abstract: Three-terminal devices with conduction channels formed by quasi-metallic carbon nanotubes (CNTs) are shown to operate as nanotube-based field-effect transistors under strong magnetic fields. The off-state conductance of the devices varies exponentially with the magnetic flux intensity. We extract the quasi-metallic CNT chirality as well as the characteristics of the Schottky barriers formed at the metal-nanotube contacts from the temperature-dependent magnetoconductance measurements.

The Electric Field

Abstract: 9. a) Find the electric field at the point A (8,0) due to the charges Q1 (0,-6) = 2 μC and Q2 (0,6) = 2 μC and where the coordinates are measured in meters. b) What is the total force exerted by Q1 and Q2 on a charge Q3 = 6 μC located at A. c) Find the electric potential at A (8,0) and B (0,0). d) How much work is required to carry a 6 μC from A (8,0) to O (0,0). Answer: a) = A E r 216 i r N/C. b) ..... c) VA = 3600 V; VO = 6000 V. d) WA→O = 0.144 J

Sub-10 nm transparent all-around-gated ambipolar ionic field effect transistor

Abstract: In this paper, we developed a versatile ionic field effect transistor (IFET) which has an ambipolar function for manipulating molecules regardless of their polarity and can be operated at a wide range of electrolytic concentrations (10−5 M–1 M). The IFET has circular nanochannels radially covered by gate electrodes, called “all-around-gate”, with an aluminum oxide (Al2O3) oxide layer of a near-zero surface charge. Experimental and numerical validations were conducted for characterizing the IFET. We found that the versatility originated from the zero-charge density of the oxide layer and all-around-gate structure which increased the efficiency of the gate effect 5 times higher than a previously developed planar-gate by capacitance calculations. Our numerical model adapted Poisson–Nernst–Planck–Stokes (PNPS) formulations with additional nonlinear constraints of a fringing field effect and a counter-ion condensation and the experimental and numerical results were well matched. The device can control the transportation of ions at concentrations up to 1 M electrolyte which resembles a backflow of a shale gas extraction process. Furthermore, while traditional IFETs can manipulate either positively or negatively charged species depending on the inherently large surface charge of oxide layer, the presenting device and mechanism provide effective means to control the motion of both negatively and positively charged molecules which is important in biomolecule transport through nanochannels, medical diagnosis system and point-of-care system, etc.

Solution processed large area field effect transistors from dielectrophoreticly aligned arrays of carbon nanotubes

Abstract: We demonstrate solution processable large area field effect transistors (FETs) from aligned arrays of carbon nanotubes (CNTs). Commercially available, surfactant free CNTs suspended in aqueous solution were aligned between source and drain electrodes using ac dielectrophoresis technique. After removing the metallic nanotubes using electrical breakdown, the devices displayed p-type behavior with on-off ratios up to ~ 2X10^4. The measured field effect mobilities are as high as 123 cm2/Vs, which is three orders of magnitude higher than typical solution processed organic FET devices.