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

This study reports the electrical transport and the field emission properties of individual multi-walled tungsten disulphide (WS2) nanotubes (NTs) under electron beam irradiation and mechanical stress. Electron beam irradiation is used to reduce the nanotube-electrode contact resistance by one-order of magnitude. The field emission capability of single WS2 NTs is investigated, and a field emission current density as high as 600 kA cm−2 is attained with a turn-on field of ≈100 V μm−1 and field-enhancement factor ≈50. Moreover, the electrical behavior of individual WS2 NTs is studied under the application of longitudinal tensile stress. An exponential increase of the nanotube resistivity with tensile strain is demonstrated up to a recorded elongation of 12%, thereby making WS2 NTs suitable for piezoresistive strain sensor applications.