Order Code: M841MSDS sheet
*Pre-made solutions will be coming on sale early 2017!*
Tungsten Disulfide (WS2)
Just like Molybdenum Disulfide (MoS2) Tungsten Disulfide (WS2) is a member of the family of materials knows as transition metal dichalcogenides (TMD's). These materials are much like graphene in their nature being 2d materials that have properties that differ significantly than those of their bulk properties. WS2 is one of the most studied TMD's in literature at the moment due to many of its unique properties.
At Ossila we sell a range of WS2 products; including powders for depositing monolayer and multilayers. In addition we offer pre-made solutions of these powders for quick and easy deposition.
At Ossila we have a range of different Tungsten Disulfide powders for sale including monolayer WS2 (M841), and multi-layer WS2 (M851). These materials come packed as dry powders and ready for re-dispersion within the users solvent of choice. In addition we sell pre-made solutions using M841 and M851 and concentrations of 1 mg.ml-1 and 0.1 mg.ml-1.
|Flake Size||0.1-4 μm||~0.2-10 μm|
|Flake Thickness||0.6-1.2 nm||0.6 - 6 nm|
|Single layer ratio||95%||N/A|
|Packaging Information||Light resistant bottle||Light resistant bottle|
|Solution Volume||100 ml||100 ml||100 ml||100 ml|
|Concentration||1 mg.ml-1||0.1 mg.ml-1||1 mg.ml-1||0.11 mg.ml-1|
|Packaging Information||4 x 25 ml Bottles||4 x 25 ml Bottles||4 x 25 ml Bottles||4 x 25 ml Bottles|
Tungsten disulfide (WS2) in bulk has been used for many years as a dry lubricant due to it exhibiting similar properties as Molybdenum disulfide (MoS2), including low coefficient of friction, high chemical stability, and thermal stability. In 1992 it was discovered that due to its structure WS2 was capable of forming nanotube structures. These nanotubes were the first examples of WS2 being used as a low dimensional material.
After the discovery of simple mechanical exfoliation techniques to isolate single layers of 2d materials it was possible to study the properties of WS2 flakes. It was shown that, just like MoS2, the band-gap of WS2 change from an indirect band-gap of 1.4eV to a direct band-gap of 2eV when changing from a bulk material to a 2d material. Due to its band-gap WS2 is seen as a significantly interesting material for may areas of application.
Just like MoS2, WS2 possesses high on/off ratio in field effect transistors, controllable spin and valley polarisation, strong geometrical confinement of excitons and tunable photoluminescence. In addition WS2 could see increased interest in areas such as photodetectors and multi-junction photovoltaics.
Tungsten disulfide readily goes into dispersion in a range of different polar solvents. At Ossila, we have found that the most stable dispersion for mono-layers and multi-layers can be produced using the following recipe:
- Weigh out desired amount of material, can go up to 1 mg.ml-1.
- Add 1:1 ratio of ethanol to deionized water.
- Shake vigorously to break up material.
- A 2 hour treatment in an ultrasonic bath will homogeneously disperse the material (40 kHz, 100 W ultrasonic bath).
|HOMO/LUMO||HOMO = 5.82 eV; LUMO = 3.84 eV|
|Bandgap||Eg = 1.98 eV (low dimensional bandgap), Eg = 1.4eV (bulk bandgap)|
|Recommended Solvents||H2O, NMP, Ethanol, IPA|
|Synonyms||Tungsten(4+) disulfide, tungsten sulfide|
|Classification / Family||
2D semiconducting materials, monolayer materials, thin-layered transition-metal dichalcogenides (TMDs), n-type semiconductors
- Electrically Tunable Valley-Light Emitting Diode (vLED) Based on CVD-Grown Monolayer WS2, W. Yang et al., Nano Lett., 16 (3), 1560–1567 (2016); DOI: 10.1021/acs.nanolett.5b04066
- Synthesis and Transfer of Large-Area Monolayer WS2 Crystals: Moving Toward the Recyclable Use of Sapphire Substrates, Z. Xu et al., ACS Nano, 9(6), 6178-6187 (2015); DOI: 10.1021/acsnano.5b01480.
- Light Generation and Harvesting in a van der Waals Heterostructure, O. Lopez-Sanchez et al., ACS Nano, 8 (3), 3042–3048 (2014); DOI: 10.1021/nn500480u.
- Chemically Driven Tunable Light Emission of Charged and Neutral Excitons in Monolayer WS2, N. Peimyoo et al., ACS Nano, 8 (11), 11320–11329 (2014); DOI: 10.1021/nn504196n
- Exciton and charge carrier dynamics in few-layer WS2, V. Vega-Mayoral et al., Nanoscale, 8, 5428 (2016); DOI: 10.1039/c5nr08384b.
- Identification of individual and few layers of WS2 using Raman Spectroscopy, A. Berkdemir et al., Sci. Rep., 3, 1755 (2013); doi:10.1038/srep01755.
- Direct Observation of Degenerate Two-Photon Absorption and Its Saturation in WS2 and MoS2 Monolayer and Few-Layer Films, S. Zhang et al., ACS Nano, 9 (7), 7142–7150 (2015); DOI: 10.1021/acsnano.5b03480.
- Layered semiconductortungsten disulfide: photoactive material in bulk heterojunction solar cells, M. Shanmugam et al., Nano Energy 2, 419–424 (2013); http://dx.doi.org/10.1016/j.nanoen.2012.11.011.
To the best of our knowledge, the technical information provided here is accurate. However, Ossila assume no liability for the accuracy of this information. The values provided here are typical at the time of manufacture and may vary over time and from batch to batch.