Enhancing charge-density-wave order in 1T-TiSe2 nanosheet by encapsulation with hexagonal Boron Nitride

Abstract

Layered transition metal dichalcogenides (TMDs) provide an ideal platform for exploring the effects of dimensionality on correlated electronic phases such as charge density wave (CDW) order. When TMDs are reduced in thickness to the 2-D limit, it is expected that the substrates will exert considerable influence on the electron states. Here we report a study of the charge density wave (CDW) state in 1T-TiSe2 nanosheets of different thicknesses when the sheets are encapsulated by hexagonal Boron Nitride (h-BN) or supported on SiO2 substrate. Our results show that dimensionality reduction results in an enhancement of CDW order and that disorder and substrate phonons tends to destroy CDW order, preventing observation of intrinsic CDW transition in ultrathin samples. Encapsulated 10 nm thick 1T-TiSe2 samples exhibit intrinsic CDW with transition temperature as high as 235 K. Our study points out that choosing the right substrate is important in the search for room temperature CDW materials.

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Cited by in corpus (7)

• On the origin of the anomalous peak in the resistivity of TiSe${}_2$
• Superconductivity induced by gate-driven hydrogen intercalation in the charge-density-wave compound 1T-TiSe2
• First-principles study on the electrical resistivity in zirconium dichalcogenides with multi-valley bands: mode-resolved analysis of electron-phonon scattering
• Optically induced symmetry breaking due to nonequilibrium steady state formation in charge density wave material 1T-TiSe2
• Persistence of charge ordering instability to Coulomb engineering in the excitonic insulator candidate TiSe${}_2$
• Structural, elastic, bonding, optoelectronic, and some thermo-physical properties of transition metal dichalcogenides ZrX2 (X = S, Se, Te): Insights from ab-initio calculations
• Doping-induced nematic and stripe orders within the charge density wave state of TiSe${}_2$