Field effect

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

Intense laser field effect on impurity states in a semiconductor quantum well: transition from the single to double quantum well potential

Abstract: In this work are studied the intense laser effects on the impurity states in GaAs-Ga1−xAlxAs quantum wells under applied electric and magnetic fields. The electric field is taken oriented along the growth direction of the quantum well whereas the magnetic field is considered to be in-plane. The calculations are made within the effective mass and parabolic band approximations. The intense laser effects have been included through the Floquet method by modifying the confinement potential associated to the heterostructure. The results are presented for several configurations of the dimensions of the quantum well, the position of the impurity atom, the applied electric and magnetic fields, and the incident intense laser radiation. The results suggest that for fixed geometry setups in the system, the binding energy is a decreasing function of the electric field intensity while a dual monotonic behavior is detected when it varies with the magnitude of an applied magnetic field, according to the intensity of the laser field radiation.

Two- and four-probe field-effect and Hall mobilities in transition metal dichalcogenide field-effect transistors

Abstract: We have fabricated WS2 and MoS2 multilayer field-effect transistors (FETs) to compare two-probe and four-probe field-effect and Hall mobility measurements. Hall mobility provides accurate information and shows the largest value, whereas field-effect mobility shows small values. The influence of contact resistance is not negligible in the two-probe field-effect mobility measurement. The current–voltage characteristics of Cr/Au (8/80 nm) contacts exhibit ohmic behavior in the WS2 multilayer FET and non-linear behavior in the MoS2 multilayer FET. Regardless of the electrical characteristics of the contacts, the field-effect mobility is much lower than the Hall mobility. Electrical contacts in the WS2 or MoS2-based FETs produce a non-discountable influence on the field-effect mobility estimation in the two-probe configuration. When the carrier concentration is not linearly dependent on gate voltage, the equivalence of field-effect and Hall mobilities does not hold. In this case, field-effect mobility provides only a rough estimate of Hall mobility.

Poly(3,3‴-didodecylquarterthiophene) field effect transistors with single-walled carbon nanotube based source and drain electrodes

Abstract: A solution processable method for employing single-walled carbon nanotubes (SWCNTs) as bottom contact source/drain electrodes for a significant reduction of contact resistance in poly(3,3‴-didodecylquarterthiophene) based organic field effect transistors (OFETs) is proposed. A two order of magnitude reduction in contact resistance and up to a threefold improvement in field effect mobilities were observed in SWCNT contacted OFETs as opposed to similar devices with gold source/drain electrodes. Based on Kelvin probe measurements, this improvement was attributed to a reduction in the Schottky barrier for hole injection into organic semiconductor.

Influence of surface‐conductivity nonuniformity on charge accumulation of GIS downsized model spacer under DC field application

Abstract: When a DC voltage is applied to an insulating spacer, the electric field distribution around it is determined by the resistivity of the material. Consequently, charges are accumulated on the surface of the insulator, and its breakdown voltage may become low. In this paper, the charge density distribution of the insulator is measured. The measured data indicate that the surface conductance is the main factor in charge accumulation. Therefore, the conductivity of the insulator is also measured, and the influence of the surface conductivity on charge accumulation is examined both experimentally and by numerical computation. It is confirmed that nonuniformity of surface conductivity is responsible for charge accumulation and the conductivity of the insulator in atmospheric-pressure SF6 is estimated to be . © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(2): 29–36, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22272