Van der Waals Pinning Strategy for High Electrical Breakdown Resistance in 2D-Material Electronics

The performance and reliability of electronic devices based on 2D materials under high electric fields are still the main issues limiting their rapid development. Many works have reported the electrical breakdown of channel materials and the breakdown electric field (E_BD) has a wide distribution spanning at least one order of magnitude. hBN encapsulation has been demonstrated to be an effective strategy to improve the electric-field tolerance of 2D materials (e.g., 2H-MoTe₂), which can effectively shield channel materials from contamination of O₂ and H₂O and further increase its E_BD. However, a new mechanism of the protective effect of hBN that is different from the widely accepted passivation effect of hBN is revealed. Combining experimental characterizations, molecular dynamics, and density functional theory simulations, it is find that the formation of the hBN/MoTe₂ interface can reduce the atomic activity of Te and introduce a physical barrier that prevents Te dissociation, ultimately improving the electric field tolerance. By employing dual hBN encapsulation and interface cleaning, the breakdown electric field and current are significantly increased by 150% and 210%, respectively. This approach offers a promising way to enhance the electric-field tolerance of 2D semiconductors and thus achieve robust 2D electronic devices.