Electronic structures of layered Ta₂NiS₅ single crystals revealed by high-resolution angle-resolved photoemission spectroscopy

Abstract

Using high-resolution angle-resolved photoemission spectroscopy (ARPES), we systematically studied the electronic structures of quasi-one-dimensional (1D) ternary material Ta2NiS5 single crystals.

Band hybridization at the semimetal-semiconductor transition of Ta2NiSe5 enabled by mirror-symmetry breaking

“…3(f) should therefore not be interpreted as a larger hybridization effect at Z than at Γ; rather, the uppermost valence bands here are simply at a lower energy due to hopping processes perpendicular to the chains, that are largely unrelated to the monoclinic distortion. A similar dispersion is observed in the S-analogue, Ta 2 NiS 5 35 . Thus, for considering the effects of the band hybridisation at the 327 K phase transition, we focus on the bands around the Γ point, where the bands overlap in the tetragonal phase and thus dominant hybridisation effects can be expected, as are indeed found in the monoclinic phase.…”

Review of Anisotropic 2D Materials: Controlled Growth, Optical Anisotropy Modulation, and Photonic Applications

“…As a potential excitonic insulator, Ta 2 NiS 5 monolayer is constituted by NiS 4 and TaS 6 units, which form linear chains along the a ‐axis and the zigzag chains in the c ‐axis. [ 54 ] The experimental results have confirmed its strong optical and electrical anisotropy, [ 55 ] which has not been observed in its binary counterpart TaS 2 . ZrGeTe 4 is another narrow bandgap semiconductor (0.7 eV) with a similar 1D chain‐like structure.…”

In-plane anisotropic electronics based on low-symmetry 2D materials: progress and prospects

“…Nowadays, many 2D ternary transition metal chalcogenides (i.e., Ta 2 NiS 5 , TaIrTe 4 ) have been successfully fabricated and are good candidates for excitonic insulator and type II Weyl semimetals. 49,118,119 In particular, the crystal structure of bulk Ta 2 NiS 5 is shown in Fig. 3.…”