||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
||Synthetic - chemical vapour transport (CVT)
||2D CDW materials
Tantalum diselenide (TaSe2), with a crystal structure of hexagonal symmetry, is another family member of transition metal dichalcogenides (TMDCs). It is metallic nature at room temperature.
In its bulk form, 2H-TaSe2 showed two-step charge-density-wave (CDW) transitions. The first transition from the metallic phase to the incommensurate charge-density-wave (ICDW) phase was at 123K, The next was a commensurate charge-density-wave (CCDW) phase transition at 90K, followed by a superconducting transition at low temperature (Tc ∼ 0.2 K).
Besides being an important CDW material, TaSe2 has several other interesting applications. It can function as an interconnect in devices, as well as an energy storage device material with intercalation of lithium ions and high volumetric capacitors.
Tantalum diselenide powder is obtained via the CVT method, with a purity in excess of 99.995% achieved.
Tantalum diselenide powder is suitable for liquid chemical exfoliation to prepare TaSe2 nanosheets and nanoparticles down to few-layer films. TaSe2 powder is also used in the preparation of mono-layer and few-layer films via chemical vapour deposition (CVD).
Literature and Reviews
Mechanical Exfoliation and Characterization of Single and Few-Layer Nanosheets of WSe2 , TaS2 , and TaSe2, H. Li et al, small, 9, No. 11, 1974–1981 (2013); DOI: 10.1002/smll.201202919.
Zone-Folded Phonons and the Commensurate−Incommensurate Charge-Density-Wave Transition in 1T‑TaSe2 Thin Films, R. Samnakay et al., Nano Lett., 15, 2965−2973 (2015); DOI: 10.1021/nl504811s.
Direct observation of an optically induced charge density wave transition in 1T-TaSe2, S. Sun et al., Phys. Rev. B., 92, 224303 (2015); doi: 10.1103/PhysRevB.92.224303.
Contrast and Raman spectroscopy study of single- and few-layered charge density wave material: 2H-TaSe2, P. Hajiyev et al., Sci. Rep., 3 : 2593 (2013); DOI: 10.1038/srep02593.
Structural, electronic and vibrational properties of few-layer 2H- and 1T-TaSe2, J. Yan et al., Sci. Rep., 5 : 16446 (2013); DOI: 10.1038/srep16646.
Dimensional reduction and ionic gating induced enhancement of superconductivity in atomically thin crystals of 2H-TaSe2, Nanotech., 30, 035702 ((2019); doi:10.1088/1361-6528/aaea3b.