Monolayer WS2

Order Code: M841
MSDS sheet


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General Information

CAS number 12138-09-9
Chemical formula WS2
Molecular weight 247.97 g/mol
HOMO/LUMO/Bandgap HOMO = 5.82 eV; LUMO = 3.84 eV (Eg = 1.98 eV)
Synonyms Tungsten(4+) disulfide, tungsten sulfide
Classification / Family 2D semiconducting materials, monolayer materials, thin-layered transition-metal dichalcogenides (TMDs), n-type semiconductors

Product Details

Purity 99.9%
Single layer ratio 95%
Diameter 0.1~4 µm
Melting point N/a (decomposes to tungsten and sulfur)
Colour Black powder/granules

Chemical Structure

chemical structure of WS2
Structure of monolayer Tungsten disulfide (WS2); CAS no. 12138-09-9.


Monolayer tungsten disulfide (WS2), a family member of the atomically thin-layered transition-metal dichalcogenides (TMDs) has attracted great attention for its intriguing electrical and optical properties. It finds various applications in organic electronics such as solar cells, light-emitting diodes and photosensors.

Monolayer WS2 has a direct bandgap of ~2.0 eV while the bulk WS2 is generally an n-type indirect semiconductor with a bandgap of ~1.4 eV. Comparing with bulk WS2 indirect semiconductor, monolayer WS2 possesses high on/off ratio, controllable spin and valley polarisation, strong geometrical confinement of excitons and tunable photoluminescence.

Characterisation (SEM)

sem image of WS2 monolayer

SEM image of monolayer tungsten disulfide. 

Literature and Reviews

  1. 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
  2. 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.
  3. 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.
  4. 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