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Description
The performance and scalability of two-dimensional (2D) materials based quantum electronics devices critically depends on the choice of gate dielectric. In gate-defined quantum devices, high-κ dielectrics enhance electrostatic control and reduce gate leakage. Hexagonal boron nitride (hBN), a 2D layered material, has become a widely used dielectric due to the clean interface it forms with 2D materials and its wide band gap; however, its relatively low dielectric constant (κ ≈ 2.5–4) [1] limits the gate capacitance, and therefore the charge carrier density.
In this work, we investigate Lanthanum OxyBromide (LaOBr) as an alternative 2D crystalline layered dielectric. LaOBr combines a high dielectric constant with a wide band gap and structural compatibility with van der Waals heterostructures [2], making it a promising material to overcome the limitations of hBN while preserving the benefits of a clean 2D-2D interface.
To evaluate LaOBr as a suitable gate dielectric, we fabricated 2D material-based field-effect devices and characterized key electrical properties, focusing on the gate leakage current, device carrier mobility, gate dielectric breakdown, and dielectric constant. This work will prompt the study of other layered high-k dielectrics as alternatives to hBN, providing additional tuning knobs for heterostructure fabrication.
References:
[1] J. Boddison-Chouinard, et al. npj 2D Mater Appl 7, 50 (2023)
[2] A. Soll et al ACS Nano 2024, 18, 15, 10397–10406 (2024)
| Keyword-1 | Low-T Electronic Transport |
|---|---|
| Keyword-2 | 2D Materials |
| Keyword-3 | 2D Gate Dielectrics |