@article { ISI:000327521300003, title = {Superior field emission properties of layered WS2-RGO nanocomposites}, journal = {Scientific Reports}, volume = {3}, year = {2013}, month = {NOV}, pages = {3282}, publisher = {NATURE PUBLISHING GROUP}, address = {MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND}, abstract = {

We report here the field emission studies of a layered WS2-RGO composite at the base pressure of similar to 1 x 10(-8) mbar. The turn on field required to draw a field emission current density of 1 mu A/cm(2) is found to be 3.5, 2.3 and 2 V/mu m for WS2, RGO and the WS2-RGO composite respectively. The enhanced field emission behavior observed for the WS2-RGO nanocomposite is attributed to a high field enhancement factor of 2978, which is associated with the surface protrusions of the single-to-few layer thick sheets of the nanocomposite. The highest current density of similar to 800 mu A/cm(2) is drawn at an applied field of 4.1 V/mu m from a few layers of the WS2-RGO nanocomposite. Furthermore, first-principles density functional calculations suggest that the enhanced field emission may also be due to an overalp of the electronic structures of WS2 and RGO, where graphene-like states are dumped in the region of the WS2 fundamental gap.

}, issn = {2045-2322}, doi = {10.1038/srep03282}, author = {Rout, Chandra Sekhar and Joshi, Padmashree D. and Kashid, Ranjit V. and Joag, Dilip S. and More, Mahendra A. and Simbeck, Adam J. and Washington, Morris and Nayak, Saroj K. and Late, Dattatray J.} } @article { ISI:000341152600073, title = {Enhanced field emission properties of doped graphene nanosheets with layered SnS2}, journal = {Applied Physics Letters}, volume = {105}, number = {4}, year = {2014}, month = {JUL}, pages = {043109}, publisher = {AMER INST PHYSICS}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

We report here our experimental investigations on p-doped graphene using tin sulfide (SnS2), which shows enhanced field emission properties. The turn on field required to draw an emission current density of 1 mu A/cm(2) is significantly low (almost half the value) for the SnS2/reduced graphene oxide (RGO) nanocomposite (2.65 V/mu m) compared to pristine SnS2 (4.8 V/mu m) nanosheets. The field enhancement factor beta (similar to 3200 for the SnS2 and similar to 3700 for SnS2/RGO composite) was calculated from Fowler-Nordheim (F-N) plots, which indicates that the emission is from the nanometric geometry of the emitter. The field emission current versus time plot shows overall good emission stability for the SnS2/RGO emitter. The magnitude of work function of SnS2 and a SnS2/graphene composite has been calculated from first principles density functional theory (DFT) and is found to be 6.89 eV and 5.42 eV, respectively. The DFT calculations clearly reveal that the enhanced field emission properties of SnS2/RGO are due to a substantial lowering of the work function of SnS2 when supported by graphene, which is in response to p-type doping of graphene. (C) 2014 AIP Publishing LLC.

}, issn = {0003-6951}, doi = {10.1063/1.4892001}, author = {Rout, Chandra Sekhar and Joshi, Padmashree D. and Kashid, Ranjit V. and Joag, Dilip S. and More, Mahendra A. and Simbeck, Adam J. and Washington, Morris and Nayak, Saroj K. and Late, Dattatray J.} } @article { ISI:000344791100009, title = {Metallic few-layer flowerlike VS2 nanosheets as field emitters}, journal = {European Journal of Inorganic Chemistry}, number = {31}, year = {2014}, month = {NOV}, pages = {5331-5336}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

We report first-principles DFT calculations of the single-layer VS2 work function, the experimental synthesis of flower-like few-layer-thick VS2 nanosheets by a simple one-step hydrothermal method, and the investigation of their field emission properties. The turn-on field required to draw emission current densities of 1 and 10 mu A/cm(2) were 4 and 5.01 V/mu m, respectively. The observed turn-on field values are attributed to the high field enhancement factor (ca. 2500), which is due to presence of sharp protrusions in the VS2 nanosheets. Furthermore, the field-emission current stability of the VS2 emitter shows stable behavior over a period of 12 h. Further, DFT calculations show that the work function (f) of the single-layer VS2 emitter is 6.01 eV.

}, keywords = {Density functional calculations, field emission, Layered compounds, Nanostructures, Sulfur, Vanadium}, issn = {1434-1948}, doi = {10.1002/ejic.201402448}, author = {Rout, Chandra Sekhar and Khare, Ruchita T. and Kashid, Ranjit V. and Joag, Dilip S. and More, Mahendra A. and Lanzillo, Nicholas A. and Washington, Morris and Nayak, Saroj K. and Late, Dattatray J.} }