Growth and microstructural evolution of WS_2 nanostructures with tunable field and light modulated electrical transport

摘要

Graphical abstractDisplay OmittedHighlights•Control on microstructural evolution of nanostructures in CVD growth from 1D WO3nanorod to 1D and 2D WS2nanostructures.•Site specific sequential transformation of WS2nanostructures with aid of electron microscopic observations.•Nanoscale device formation using hybrid WS2nanostructures with controlled modulation using light as well as electric field.AbstractWe report CVD growth of WS2nanostructures with the ability to control the evolution of 1D to 2D microstructural changes for light and field effect transistor applications. Detailed mechanistic growth sequences from WO3nanorod to nanotube, monolayer and pyramidal structures of WS2has been achieved using atmospheric pressure chemical vapor deposition (APCVD). Electron microscopy and Raman spectroscopy analysis showed the growth evolution of different nanostructures and their formation mechanism. Location specific growth of different WS2nanostructures can be achieved by drop casting dispersed WO3nanorods on required substrate. Layer dependent photoluminescence (PL) properties of WS2indicate the effect of quantum confinement induced radiative recombination and enhanced PL intensity in monolayer WS2provides suitability for nanoscale photodetector application. The fabricated device shows light as well as field modulated switching at ultra-low biased voltage in hybrid WS2nanostructure that contains 1D (nanotube)-2D (flake) interface. The demonstrated aspects of CVD growth and hybrid device characteristics provide opportunities to tune electrical transport of WS2nanostructures at low active power.