Field effect

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

Determination of Quantum Capacitance and Band Filling Potential in Graphene Transistors with Dual Electrochemical and Field-Effect Gates

Abstract: We report here an investigation of graphene field-effect transistors (G-FETs) in which the graphene channel is in contact with an electrolyte phase. The electrolyte and the ultrathin nature of graphene allow direct measurement of the channel electrochemical potential versus a reference electrode also in contact with the electrolyte. In addition, the electrolyte can be used to gate the graphene; i.e., a dual-gate structure is realized. We employ this electrolyte modified G-FET architecture to (1) track the Fermi level of the graphene channel as a function of gate bias, (2) determine the density of states (i.e., the quantum capacitance CQ) of graphene, and (3) separate the gate induced band filling potential δ from the electrochemical double-layer charging potential ΔϕEDL. Additionally, we are able to determine the electric double-layer capacitance CEDL for the graphene/electrolyte interface, which is ∼5 μF/cm2, the same order of magnitude as CQ. Overall, the electrolyte modified G-FETs provide an excellent...

Field-effect experiments in NdBa2Cu3O7−δ ultrathin films using a SrTiO3 single-crystal gate insulator

Abstract: We report on the electrostatic modulation of superconductivity in very thin films of cuprate superconductors using a field-effect device based on a SrTiO3 single-crystal gate insulator A Tc modulation of 35 K and a 37% change of the normal state resistance have been observed in an epitaxial bilayer composed of an insulating PrBa2Cu3O7−δ layer deposited on top of a superconducting NdBa2Cu3O7−δ film, two unit cells thick To achieve large electric fields, the thickness of the commercial dielectric single-crystal SrTiO3 substrate (also used as the gate insulator) was reduced to 110 μm The dielectric properties of the gate insulator were characterized as a function of temperature and electric field and the magnitude of the field effect was quantified A Tc enhancement of 28 K was obtained for an applied field of −18×106 V/m, corresponding to a polarization of −4 μC/cm2

JFET controlled schottky barrier diode

Abstract: A JFET controlled Schottky barrier diode includes a p-type diffusion region integrated into the cathode of the Schottky diode to form an integrated JFET where the integrated JFET provides on-off control of the Schottky barrier diode. The p-type diffusion region encloses a portion of the forward current path of the Schottky barrier diode where the p-type diffusion region forms the gate of the JFET and the enclosed portion of the forward current path forms the channel region of the JFET. By applying a reverse biased potential to the gate of the JEFT with respect to the anode of the Schottky diode, the forward current of the Schottky diode can be pinched off, thereby providing on-off control over the Schottky diode forward current.

SiO2/Gd2O3/GaN Metal Oxide Semiconductor Field Effect Transistors

Abstract: GaN-based metal oxide semiconductor field effect transistors (MOSFETs) were demonstrated using a stacked gate oxide consisting of single-erystal Gd 2 O 3 and amorphous SiO 2 . Gd 2 O 3 provides a good oxide/semiconductor interface and SiO 2 reduces the gate leakage current and enhances oxide breakdown voltage. Charge modulation of the n-channel depletion mode MOSFET was achieved for gate voltage from +2 to -4 V. The source-drain breakdown voltage exceeded 80 V. An intrinsic transconductance of 61 mS/mm was obtained at a gate-source and drain-source bias of -0.5 and 20 V, respectively. This is the first demonstration of epitaxial Gd 2 O 3 growth on GaN and the first use of Gd 2 O 3 as an insulating layer for nitride electronic device applications.

Proximity and anomalous field-effect characteristics in double-wall carbon nanotubes

Abstract: Proximity effect on field-effect characteristic (FEC) in double-wall carbon nanotubes (DWCNTs) is investigated. In a semiconductor-metal (S-M) DWCNT, the penetration of electron wavefunctions in the metallic shell to the semiconducting shell turns the original semiconducting tube into a metal with a non-zero local density of states at the Fermi level. By using a two-band tight-binding model on a ladder of two legs, it is demonstrated that anomalous FEC observed in so-called S-M type DWCNTs can be fully understood by the proximity effect of metallic phases.