Ossila/Tungsten Diselenide Crystal/Large/M2111A00

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General Information

Product Details

General description

Bulk tungsten diselenide (WSe₂) has a high absorption coefficient, high photostability, and a band-gap of 1.2 eV. It is an indirect band-gap semiconducting material that can be both n- and p-doped. The ambipolar nature of WSe₂ makes it possible to create electronic devices that include p−n junctions or complementary logic circuits.

Tungsten diselenide single layers are composed of a layer of tungsten atoms positioned between two layers of selenium atoms, with each tungsten atom coordinating through strong covalent-ionic bonds to six selenium atoms in a trigonal prismatic geometry.  As occurs in graphene, black phosphorus and other TMDC materials, multuilayer structures are stabilised by weak Van de Waal forces. These forces are strong enough to hold layers together, but weak enough to allow mechanical exfoliation.

With a lattice structure similar to MoSe₂, WSe₂ single layers are semiconductors with a trigonal (2H) structure. By reacting with n-butyllithium, the 2H-WS₂ can undergo a phase change to 1T-WSe₂ (this process being totally reversible).

Applications

Monolayer or few-layer WS₂ films that are mechanically exfoliated from bulk WS₂ crystals have been explored for applications in FETs, electrochemical cells, thermoelectrics, sensors, and light-emitting diodes.

The energy gap of WSe₂ (1.2 - 1.4 eV) makes it perfect for applications in photovoltaics and solar cells.

Synthesis

Tungsten disulfide WS₂ is manufactured via chemical vapour transport (CVT) crystallisation, with a purity in excess of 99.999%.

Usage

Tungsten disulfide WS₂ can be used to create monolayer and few-layer WS₂ by mechanical or liquid exfoliation.

Literature and Reviews

1. Layer-dependent electronic structure of an atomically heavy two-dimensional dichalcogenide, P-C. Yeh et al., Phys. Rev. B 91, 041407 (2015); DOI: 10.1103/PhysRevB.91.041407.
2. Strain-Induced Indirect to Direct Bandgap Transition in Multilayer WSe2,S. B. Desai et al., Nano Lett., 14 (8), 4592–4597 (2014); DOI: 10.1021/nl501638a.
3. Large-Area Synthesis of Highly Crystalline WSe2 Monolayers and Device Applications, J. Huang et al., ACS Nano, 8 (1), 923–930 (2014); DOI: 10.1021/nn405719x.
4. Preparation and Applications of Mechanically Exfoliated Single-Layer and Multilayer MoS2 and WSe2 Nanosheets, H. Li et al., Acc. Chem. Res., 47, 1067−1075 (2014); DIO: 10.1021/ar4002312.
5. Large-area synthesis of monolayer WSe2 on a SiO2/Si substrate and its device applications, J. Huang et al., Nanoscale, 7, 4193 (2015); DOI: 10.1039/c4nr07045c.

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.