Semiconductors

Unravelling the band structure features of hgte nanoplatelets in ultrathin limit

V. G. Kuznetsov^a, A. A. Gavrikov^b, A. V. Kolobov<sup>b

a</sup> Ioffe Institute, St. Petersburg
^b Herzen State Pedagogical University of Russia, St. Petersburg

Abstract: The band structure of mercury telluride (HgTe) nanoplatelets in the two-monolayer (2ML) limit was studied taking into account spin-orbit coupling and using various density functional theory (DFT) types. Single-layer (1ML) and two-layer (2ML) HgTe nanoplatelets in the sphalerite phase, as well as bulk HgTe, were considered. It was demonstrated that strong spin-orbit coupling, combined with two-dimensional quantum confinement, lead to significant changes in the electronic band structure of ultrathin two-dimensional (2D) HgTe nanoplatelets and the ordering of their boundary bands compared to a three-dimensional material. Calculations of band structure of 2D-nanoplatelets in ultrathin limit revealed a number of specific features: (i) the nature of band structure of 1ML HgTe (inverted/non-inverted band order) depends on the type of density functional used; (ii) the regular band structure of 1ML-HgTe has a non-inverted (normal) band order, and the nanoplate itself is a direct-gap semiconductor at the Г point; (iii) the band structure of 2ML-HgTe has no forbidden band and has an inverted band order; (iv) the band structure of 2ML-HgTe near the Fermi level exhibits behavior characteristic of a type-II Weyl semimetal.

Keywords: mercury telluride, 2D-nanoplatelets, inverted band structure, type-II weyl semimetal.

Received: 16.09.2025
Revised: 26.10.2025
Accepted: 06.11.2025

DOI: 10.61011/FTT.2025.11.62130.255-25

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