Ambipolar conduction in gated tungsten disulphide nanotube.

Devices based on transition metal dichalcogenide nanotubes hold great potential for electronic and optoelectronic applications. Herein, the electrical transport and photoresponse characteristics of a back-gate device with a channel made of a single tungsten disulfide (WS) nanotube are investigated as functions of electric stress, ambient pressure, and illumination. As a transistor, the device exhibits p-type conduction, which can be transformed into ambipolar conduction at a high drain-source voltage.

The Superconducting Mechanism in BiS-Based Superconductors: A Comprehensive Review with Focus on Point-Contact Spectroscopy.

The family of BiS-based superconductors has attracted considerable attention since their discovery in 2012 due to the unique structural and electronic properties of these materials. Several experimental and theoretical studies have been performed to explore the basic properties and the underlying mechanism for superconductivity. In this review, we discuss the current understanding of pairing symmetry in BiS-based superconductors and particularly the role of point-contact spectroscopy in unravelling the mechanism underlying the superconducting state.

Field enhancement induced by surface defects in two-dimensional ReSe field emitters.

The field emission properties of rhenium diselenide (ReSe) nanosheets on Si/SiO substrates, obtained through mechanical exfoliation, have been investigated. The n-type conduction was confirmed by using nano-manipulated tungsten probes inside a scanning electrode microscope to directly contact the ReSe flake in back-gated field effect transistor configuration, avoiding any lithographic process. By performing a finite element electrostatic simulation of the electric field, it is demonstrated that the use of a tungsten probe as anode, at a controlled distance from the ReSe emitter surface, allows the collection of emitted electrons from a reduced area that furtherly decreases by reducing the tip-sample distance, allowing a local characterization of the field emission properties.

WS Nanotube Transistor for Photodetection and Optoelectronic Memory Applications.

Nanotube and nanowire transistors hold great promises for future electronic and optoelectronic devices owing to their downscaling possibilities. In this work, a single multi-walled tungsten disulfide (WS) nanotube is utilized as the channel of a back-gated field-effect transistor. The device exhibits a p-type behavior in ambient conditions, with a hole mobility µ ≈  1.

Multilayer WS for low-power visible and near-infrared phototransistors.

Mechanically exfoliated multilayer WS flakes are used as the channel of field effect transistors for low-power photodetection in the visible and near-infrared (NIR) spectral range. The electrical characterization as a function of the temperature reveals devices with n-type conduction and slightly different Schottky barriers at the drain and source contacts. The WS phototransistors can be operated in self-powered mode, yielding both a current and a voltage when exposed to light.