*typical representative size, areas/dimensions may vary
||Titanium selenide (TiSe2), Bis(selanylidene)titanium
|Classification / Family
Transition metal dichalcogenides (TMDCs), Charge density wave (CDW), Superconductivity, Nano-electronics, Nano-photonics, Photovoltaic, Materials science
||Synthetic - Chemical Vapour Transport (CVT)
||Semimetal, Charge density waves (CDW)
Titanium diselenide (TiSe2) is a family member of Group IV transition metal dichalcogenides (TMDCs), and is of great interest as one of the typical charge density wave (CDW) materials. It is known that the CDW characteristics of TiSe2 can be changed; they are typically suppressed. In some cases, this leads to superconductivity or magnetic order by applying high pressure or intercalation.
TiSe2 has an octahedral crystal structure (1T, space group D3d) with van der Waals stacked layers. Monolayer TiSe2 consists of stacked Se–Ti–Se atomic layers, in which Ti and Se atoms are strongly bound within the layer. 1T-TiSe2 undergoes a phase transition from a semimetal (1 × 1 × 1 normal phase) to a commensurate CDW (2 × 2 × 2 CDW) at around 200 K.
Titanium diselenide has potential applications in optoelectronics, advanced low‐power electronics, superconductors, voltage-controlled oscillators, and ultra-fast electronics.
Titanium diselenide is manufactured using chemical vapour transport (CVT) crystallisation, with crystals having a purity in excess of 99.999%.
Titanium diselenide single crystals can be used to prepare monolayer and few-layer TiSe2 by mechanical or liquid exfoliation.
Literature and Reviews
Enhancing charge-density-wave order in 1T-TiSe2 nanosheet by encapsulation with hexagonal boron nitride, L. Li et al., Appl. Phys. Lett. 109, 141902 (2016); doi: 10.1063/1.4963885.
Unveiling the charge density wave inhomogeneity and pseudogap state in 1T-TiSe2, K. Zhang et al., Sci. Bull., 63, 426–432 (2018); doi: 10.1016/j.scib.2018.02.018.
Unconventional Charge-Density-Wave Transition in Monolayer 1T‑TiSe2, K. Sugawara et al., ACS Nano, 10, 1341−1345 (2016); DOI: 10.1021/acsnano.5b06727.
Raman Characterization of the Charge Density Wave Phase of 1T-TiSe2: From Bulk to Atomically Thin Layers, D. Duong et al., ACS Nano, 11, 1034−1040 (2017); DOI: 10.1021/acsnano.6b07737.
Hydrogenation-driven phase transition in single-layer TiSe2, F. Iyikanat et al, Nanotechnology 28, 495709 (2017); doi: 10.1088/1361-6528/aa94ab.