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

Geetanjali Deokar; Nitul S Rajput; Junjie Li; Francis Leonard Deepak; Wei Ou-Yang; Nicolas Reckinger; Carla Bittencourt; Jean-Francois Colomer; Mustapha Jouiad

doi:10.3762/bjnano.9.160

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

Beilstein J Nanotechnol. 2018 Jun 7:9:1686-1694. doi: 10.3762/bjnano.9.160. eCollection 2018.

Authors

Geetanjali Deokar^{1

2}, Nitul S Rajput¹, Junjie Li³, Francis Leonard Deepak³, Wei Ou-Yang⁴, Nicolas Reckinger², Carla Bittencourt⁵, Jean-Francois Colomer², Mustapha Jouiad¹

Affiliations

¹ Department of Mechanical and Materials Engineering, Masdar Institute of Science and Technology, A part of Khalifa University of Science and Technology, 54224, Abu Dhabi, United Arab Emirates.
² Research Group on Carbon Nanostructures (CARBONNAGe), University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
³ Department of Advanced Electron Microscopy, Imaging and Spectroscopy, International Iberian Nanotechnology Laboratory (INL), Avenida Mestre Jose Veiga, Braga 4715-330, Portugal.
⁴ Engineering Research Center for Nanophotonics & Advanced Instrument, Ministry of Education, School of Physics and Materials Science, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China.
⁵ Chimie des Interactions Plasma-Surface (ChIPS), CIRMAP, Research Institute for Materials Science and Engineering, University of Mons, Mons, Belgium.

Abstract

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.

Keywords: chemical vapor deposition (CVD); field emission; molybdenum disulfide (MoS2); nanosheets; sulfurization; transmission electron microscopy (TEM).