Toward the use of CVD-grown MoS₂ nanosheets as field-emission source

Densely populated edge-terminated vertically aligned two-dimensional MoS₂ nanosheets (NSs) with thicknesses ranging from 5 to 20 nm were directly synthesized on Mo films deposited on SiO₂ by sulfurization. The quality of the obtained NSs was analyzed by scanning electron and transmission electron microscopy, and Raman and X-ray photoelectron spectroscopy. The as-grown NSs were then successfully transferred to the substrates using a wet chemical etching method. The transferred NSs sample showed excellent field-emission properties. A low turn-on field of 3.1 V/μm at a current density of 10 µA/cm² was measured. The low turn-on field is attributed to the morphology of the NSs exhibiting vertically aligned sheets of MoS₂ with sharp and exposed edges. Our findings show that the fabricated MoS₂ NSs could have a great potential as robust high-performance electron-emitter material for various applications such as microelectronics and nanoelectronics, flat-panel displays and electron-microscopy emitter tips.