Field effect

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

Controlled p- and n-type doping of Fe2O3 nanobelt field effect transistors

Abstract: Pure α-Fe2O3 nanobelts are configured as field effect transistors and electrical transport studies demonstrate their n-type behavior In order to control the electrical properties of the fabricated transistor, the nanobelt channels are doped with zinc Depending on the doping condition, α-Fe2O3 nanobelts can be modified to either p-type or n-type with enhanced conductivity and electron mobility Such behavior change is exhibited in the variation of the current-voltage (I-V) and I-Vg characteristics

Thin-film field-effect transistor with organic-inorganic hybrid semiconductor requiring low operating voltages

Abstract: A thin film transistor (TFT) device structure based on an organic-inorganic hybrid semiconductor material, that exhibits a high field effect mobility, high current modulation at lower operating voltages than the current state of the art organic-inorganic hybrid TFT devices. The structure comprises a suitable substrate disposed with the following sequence of features: a set of conducting gate electrodes covered with a high dielectric constant insulator, a layer of the organic-inorganic hybrid semiconductor, sets of electrically conducting source and drain electrodes corresponding to each of the gate lines, and an optional passivation layer that can overcoat and protect the device structure. Use of high dielectric constant gate insulators exploits the gate voltage dependence of the organic-inorganic hybrid semiconductor to achieve high field effect mobility levels at very low operating voltages. Judicious combinations of the choice of this high dielectric constant gate insulator material and the means to integrate it into the organic-inorganic hybrid based TFT structure are taught that would enable easy fabrication on glass or plastic substrates and the use of such devices in flat panel display applications.

Highly Stable and Tunable Chemical Doping of Multilayer WS2 Field Effect Transistor: Reduction in Contact Resistance.

Abstract: The development of low resistance contacts to 2D transition-metal dichalcogenides (TMDs) is still a big challenge for the future generation field effect transistors (FETs) and optoelectronic devices. Here, we report a chemical doping technique to achieve low contact resistance by keeping the intrinsic properties of few layers WS2. The transfer length method has been used to investigate the effect of chemical doping on contact resistance. After doping, the contact resistance (Rc) of multilayer (ML) WS2 has been reduced to 0.9 kΩ·μm. The significant reduction of the Rc is mainly due to the high electron doping density, thus a reduction in Schottky barrier height, which limits the device performance. The threshold voltage of ML-WS2 FETs confirms a negative shift upon the chemical doping, as further confirmed from the positions of E(1)2g and A1g peaks in Raman spectra. The n-doped samples possess a high drain current of 65 μA/μm, with an on/off ratio of 1.05 × 10(6) and a field effect mobility of 34.7 cm(2)/(V·s) at room temperature. Furthermore, the photoelectric properties of doped WS2 flakes were also measured under deep ultraviolet light. The potential of using LiF doping in contact engineering of TMDs opens new ways to improve the device performance.

Low Schottky barrier black phosphorus field-effect devices with ferromagnetic tunnel contacts.

Abstract: Black phosphorus (BP) has been recently unveiled as a promising 2D direct bandgap semiconducting material Here, ambipolar field-effect transistor behavior of nanolayers of BP with ferromagnetic tunnel contacts is reported Using TiO2/Co contacts, a reduced Schottky barrier <50 meV, which can be tuned further by the gate voltage, is obtained Eminently, a good transistor performance is achieved in the devices discussed here, with drain current modulation of four to six orders of magnitude and a mobility of μh ≈ 155 cm2 V−1 s−1 for hole conduction at room temperature Magnetoresistance calculations using a spin diffusion model reveal that the source–drain contact resistances in the BP device can be tuned by gate voltage to an optimal range for injection and detection of spin-polarized holes The results of the study demonstrate the prospect of BP nanolayers for efficient nanoelectronic and spintronic devices

Interfacial n-Doping Using an Ultrathin TiO2 Layer for Contact Resistance Reduction in MoS2

Abstract: We demonstrate a low and constant effective Schottky barrier height (ΦB ∼ 40 meV) irrespective of the metal work function by introducing an ultrathin TiO2 ALD interfacial layer between various metals (Ti, Ni, Au, and Pd) and MoS2. Transmission line method devices with and without the contact TiO2 interfacial layer on the same MoS2 flake demonstrate reduced (24×) contact resistance (RC) in the presence of TiO2. The insertion of TiO2 at the source-drain contact interface results in significant improvement in the on-current and field effect mobility (up to 10×). The reduction in RC and ΦB has been explained through interfacial doping of MoS2 and validated by first-principles calculations, which indicate metallic behavior of the TiO2-MoS2 interface. Consistent with DFT results of interfacial doping, X-ray photoelectron spectroscopy (XPS) data also exhibit a 0.5 eV shift toward higher binding energies for Mo 3d and S 2p peaks in the presence of TiO2, indicating Fermi level movement toward the conduction band (...