Nanotip Contacts for Electric Transport and Field Emission Characterization of Ultrathin MoS2 Flakes

Abstract

We report a facile approach based on piezoelectric-driven nanotips inside a scanning electron microscope to contact and electrically characterize ultrathin MoS2 (molybdenum disulfide) flakes on a SiO2/Si (silicon dioxide/silicon) substrate. We apply such a method to analyze the electric transport and field emission properties of chemical vapor deposition-synthesized monolayer MoS2, used as the channel of back-gate field effect transistors. We study the effects of the gate-voltage range and sweeping time on the channel current and on its hysteretic behavior. We observe that the conduction of the MoS2 channel is affected by trap states. Moreover, we report a gate-controlled field emission current from the edge part of the MoS2 flake, evidencing a field enhancement factor of approximately 200 and a turn-on field of approximately 40 V / μ m at a cathode–anode separation distance of 900 nm .

Contact resistance and mobility in back-gate graphene transistors

“…The isolation of graphene [1][2][3] in 2004 and, later on, of h-BN [4], phosphorene [5], S Mo 2 [6][7][8][9][10][11][12][13][14], WSe 2 [15][16][17], e PdS 2 [18,19], PtSe 2 [20,21] etc, has strongly attracted the interest of the material science community to the world of two-dimensional (2D) materials.…”

Observation of 2D Conduction in Ultrathin Germanium Arsenide Field-Effect Transistors

“… 2 , 3 Several transition metal dichalcogenides (TMDs) have promptly emerged as possible substitutes or complements to graphene 4 and have already been investigated and proposed for several applications. 5 − 13 More recently, the search for new types of 2D materials has led to the investigation of binary compounds of IV and V groups. Indeed, theoretical calculations have indicated that MX compounds, with M = Si, Ge, Sn, or Pb and X = P, As, Sb, or Bi, might have crystalline layered structures with orthorhombic ( Cmc 2 1 for SiP and Pbam for SiP 2 and GeAs 2 ) or monoclinic ( C 2/ m for GeP, GeAs, and SiAs) symmetries.…”

WS2 Nanotubes: Electrical Conduction and Field Emission Under Electron Irradiation and Mechanical Stress

“…[ 4–9 ] However, the difficulty in selecting the desired CNT properties during the production process, commonly leading to a mixture of metallic and semiconducting CNTs in the final product, makes their use in technological applications an open challenge. In recent years, inorganic layered materials, such as MoS 2, [ 10–13 ] PdSe 2, [ 14–16 ] WSe, [ 17,18 ] WS 2 , [ 19 ] and GeAs [ 20 ] have been widely studied for their unique electrical and optical properties. In particular, WS 2 has a layered structure where monolayers, constituted by a plane of W atoms sandwiched between two planes of S atoms, are piled on top of each other and bonded by weak van der Waals forces.…”