Modulating Fermi-level pinning and carrier injection efficiency in 2D β-TeO₂/metal van der Waals heterostructure via interlayer distance

TY - JOUR

T1 - Modulating Fermi-level pinning and carrier injection efficiency in 2D β-TeO2/metal van der Waals heterostructure via interlayer distance

AU - Lu, Yi

AU - Liu, Biao

AU - Ding, Yu Feng

AU - Zhao, Yu Qing

AU - Zhu, Huiping

AU - Ma, Yuan Xiao

N1 - Publisher Copyright: © 2026 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved. This article is available under the terms of the IOP-Standard License.

PY - 2026/7/31

Y1 - 2026/7/31

N2 - Two-dimensional (2D) semiconductor β-TeO2 based field-effect transistors (FETs) have attracted considerable attention in the field of microelectronic devices owing to their high on/off ratio (>106), low subthreshold swing (<60 mV dec−1), and small effective hole mass (0.51 me). The contacts between the β-TeO2 semiconductor and metals are critical for enabling multifunctional device design. Here, we employed the first-principle calculation to investigate physical properties of contacts between 2D monolayer β-TeO2 and a series of metals T/H-XA2 (X = V, Nb, Ta, and A = S, Se). The tunable sensitivity of the Schottky barrier to metal work function and the charge carrier injection efficiency with varying interlayer distance were systematically investigated. At the equilibrium interlayer distance, the contact approaches the ideal Schottky–Mott limit with Fermi-level pinning (FLP) factor |S|≈ 1. However, the tunneling probabilities for these contacts are low, varying from 0.12% for the contact with NbS2 to 4.17% for the contact with VS2. Decreasing the interlayer distance to 2.0 Å leads to an increase in tunneling probability to 17.25% for the NbS2 contact and 49.60% for the VSe2 contact. However, the FLP factor S decreases to 0.42 for electrons and 0.52 for holes, indicating enhanced FLP effects due to increased metal-induced gap states. Thus, optimizing the interlayer distance to balance carrier injection efficiency and Fermi-pinning effects is crucial for high-performance FETs. These findings provide a theoretical basis for the further design and fabrication of high-performance TeO2 based transistors in the future.

AB - Two-dimensional (2D) semiconductor β-TeO2 based field-effect transistors (FETs) have attracted considerable attention in the field of microelectronic devices owing to their high on/off ratio (>106), low subthreshold swing (<60 mV dec−1), and small effective hole mass (0.51 me). The contacts between the β-TeO2 semiconductor and metals are critical for enabling multifunctional device design. Here, we employed the first-principle calculation to investigate physical properties of contacts between 2D monolayer β-TeO2 and a series of metals T/H-XA2 (X = V, Nb, Ta, and A = S, Se). The tunable sensitivity of the Schottky barrier to metal work function and the charge carrier injection efficiency with varying interlayer distance were systematically investigated. At the equilibrium interlayer distance, the contact approaches the ideal Schottky–Mott limit with Fermi-level pinning (FLP) factor |S|≈ 1. However, the tunneling probabilities for these contacts are low, varying from 0.12% for the contact with NbS2 to 4.17% for the contact with VS2. Decreasing the interlayer distance to 2.0 Å leads to an increase in tunneling probability to 17.25% for the NbS2 contact and 49.60% for the VSe2 contact. However, the FLP factor S decreases to 0.42 for electrons and 0.52 for holes, indicating enhanced FLP effects due to increased metal-induced gap states. Thus, optimizing the interlayer distance to balance carrier injection efficiency and Fermi-pinning effects is crucial for high-performance FETs. These findings provide a theoretical basis for the further design and fabrication of high-performance TeO2 based transistors in the future.

KW - 2D van der Waals heterostructure

KW - carrier injection efficiency

KW - Fermi-level pinning

KW - first-principle calculation

KW - interlayer distance effects

UR - https://www.scopus.com/pages/publications/105046010146

U2 - 10.1088/1361-648X/ae8a9f

DO - 10.1088/1361-648X/ae8a9f

M3 - Article

AN - SCOPUS:105046010146

SN - 0953-8984

VL - 38

JO - Journal of Physics Condensed Matter

JF - Journal of Physics Condensed Matter

IS - 30

M1 - 305002

ER -