Tantalum Diselenide Crystal

Order Code: M2145A10
Not in stock


Size Product code Size description* Quantity (EA) Price
Small M2145A10 >10 mm2 1 £395.00
Medium M2145A25 >25 mm2 1 £636.00

*typical representative size, areas/dimensions may vary

General Information

CAS number 12039-55-3
Chemical formula TaSe2
Molecular weight 338.87 g/mol
Bandgap n/a
Synonyms Tantalum (IV) selenide, Bis(selanylidene)tantalum
Classification / Family Transition metal dichalcogenides (TMDCs), 2D charge density wave (CDW) materials, Nano-electronics, Nano-photonics, Superconductivity, Photovoltaic, Materials science

Product Details

Form Single Crystal
Preparation Synthetic - Chemical Vapour Transport (CVT)
Purity ≥ 99.999%
Structure Hexagonal (2H)
Electronic properties 2D CDW materials
Melting point > 1,300 °C
Appearance Dark brown

General Description

Tantalum diselenide (TaSe2) is a family member of Group VB transition metal dichalcogenides (TMDCs). Group VB is one of the most heavily-studied group of TMDCs due to their diverse permutations of stable compounds and electronic behaviour.

2H-TaSe2 is a metal (or semi-metal) with no band gap. The crystal structures of TaSe2 contain Ta in trigonal prismatic coordination within Se-Ta-Se layers. The weak interlayer van der Waals (vdW) bonding leads to various TaSepolytypes, which differ simply in the relative orientations of the layers and their stacking arrangements.

2h-tase2 and 1t-tase2 structure
The 2H and 1T crystal structure of tantalum diselenide (TaSe2).

1T-TaSe2, however, is metallic in the bulk structure but insulating in a single-layer. It has thickness- and temperature-dependent properties in the commensurate charge density wave (CCDW) accompanied by a periodic lattice distortion (PLD).

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Devices with nanometer-scale thicknesses strongly exhibit non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. In principle, such current-voltage characteristics can be used for implementing radiation-hard, all-metallic logic circuits.


Tantalum diselenide is manufactured using chemical vapour transport (CVT) crystallisation, with crystals having a purity in excess of 99.999%.


Tantalum diselenide single crystals can be used to prepare monolayer and few-layer TaSe2 by mechanical or liquid exfoliation.

Literature and Reviews

  1. All-metallic electrically gated 2H-TaSe2 thin-film switches and logic circuits, J. Renteria et al., J. Appl. Phys., 115, 034305 (2014); doi: 10.1063/1.4862336.
  2. Phonon and thermal properties of exfoliated TaSe2 thin films, Z. Yan et al.,
    J. Appl. Phys., 114, 204301 (2013); 10.1063/1.4833250.
  3. Observation of charge density waves in free-standing 1T-TaSe2 monolayers by transmission electron microscopy, P. C. Börner et al., Appl. Phys. Lett. 113, 173103 (2018); doi: 10.1063/1.5052722.
  4. Persistent Charge-Density-Wave Order in Single-Layer TaSe2, H. Ryu et al., Nano Lett., 18, 689−694 (2018); DOI: 10.1021/acs.nanolett.7b03264.
  5. Selective Fabrication of Mott-Insulating and Metallic Monolayer TaSe2, Y. Nakata et al., ACS Appl. Nano Mater., 1, 1456−1460 (2018); DOI: 10.1021/acsanm.8b00184.
  6. Fast and reliable identification of atomically thin layers of TaSe2 crystals, A. Castellanos-Gomez et al., Nano Res., 6(3): 191–199 (2013); DOI 10.1007/s12274-013-0295-9.
  7. Broken hexagonal symmetry in the locked-in state of 2Ha-TaSe2 and the discommensurate microstructure of its incommensurate CDW states, J. Phys. C: Solid State Phys., 14, 5417-5432 (1981), doi: 10.1088/0022-3719/14/35/004.
  8. Mechanical Exfoliation and Characterization of Single and Few-Layer Nanosheets of WSe2 , TaS2 , and TaSe2, H. Li et al., small, 9, 11, 1974–1981 (2013); DOI: 10.1002/smll.201202919.

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.