WS2 (2H Tungsten Disulfide)
2H-WS2 is a semiconductor with an indirect band gap of ~1.3 eV. Monolayer 2H-WS2 has a direct band gap. The layers are stacked together via van der Waals interactions and can be exfoliated into thin 2D layers. Tungsten Disulfide belongs to the group-VI transition metal dichalcogenides (TMDC).
To buy WS2 crystals please click here.
The 2H phase WS2 crystals produced at HQ Graphene have a typical lateral size of ~0.8-1 cm, are hexagonal shaped and have a metallic appearance.
The 2H WS2 is n-type semiconductor, having a typical charge carrier density of ~1014cm-3 at room temperature.
A selection of peer review publications on the WS2 crystals we sell can be found below.
| Crystal size | ~10 mm |
| Electrical properties | Semiconductor, n-type |
| Crystal structure | hexagonal |
| Unit cell parameters | a = b = 0.315 nm, c = 1.227 nm, α = β = 90, γ = 120° |
| Monolayer properties |  Link to C2DB containing calculated properties |
| Type | Synthetic |
| Purity | >99.995 % |
| Characterized by | XRD, Raman, EDX, Hall measurement |
| More information? | Please contact us by email or phone |
The single crystal 2H WS2 is characterized using:
XRD: single crystal and powder X-ray diffraction (D8 Venture Bruker and D8 Advance Bruker)EDX: Energy-dispersive X-ray spectroscopy for stoichiometric analysis
Raman: 785 nm Raman system
Hall measurement: Extraction of charge carrier density and doping in the Van der Pauw geometry.
Raman, XRD and EDX on 2H-WS2:
Click on an image to zoom
HQ Graphene Wiki on:
2H phase WS2 (Tungsten disulfide)
1. Shaojun Wang et al., "Coherent Coupling of WS2 Monolayers with Metallic Photonic Nanostructures at Room Temperature" Nano Lett. 16 (7), link to article:
http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b01475
2. Gerd Plechingeret al., "Excitonic valley effects in monolayer WS2 under high magnetic fields", Nano Lett., 2016, 16 (12), pp 7899-7904, link to article:
http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b04171
3. Beom Seo Kim et al., "Determination of the band parameters of bulk 2H-MX2 (M = Mo, W; X = S, Se) by angle-resolved photoemission spectroscopy", Nature/Scientific Reports 6, Article number: 36389 (2016), link to article:
http://www.nature.com/articles/srep36389