Two-dimensional Bi₂SeO₂ and Its Native Insulators for Next-Generation Nanoelectronics

Area of Science:

• Materials Science
• Condensed Matter Physics
• Semiconductor Physics

Background:

• Silicon (Si) is the dominant semiconductor in integrated circuits due to its stable native oxide, silicon dioxide (SiO2).
• Further scaling of silicon-based field-effect transistors (FETs) faces significant challenges.
• Existing two-dimensional (2D) materials like MoS2 lack stable, compatible native oxides, hindering their integration into advanced electronic devices.

Purpose of the Study:

• To investigate the fundamental properties of 2D bismuth selenide oxide (Bi2SeO2) and its native oxides.
• To explore the potential of Bi2SeO2 as a semiconductor for next-generation transistor technologies.
• To understand the atomic-scale structure and interfaces of Bi2SeO2 and its native oxides.

Main Methods:

• Density functional theory (DFT) and molecular dynamics (MD) simulations were employed to study intrinsic material properties.
• Scanning transmission electron microscopy (STEM) was used for atomic-scale structural analysis and interface characterization.
• Semiconductor-oxide heterostructures were modeled to extract key electronic properties.

Main Results:

• Bi2SeO2 can form compatible high-κ native oxides (Bi2SeO5) with a dielectric constant greater than 30.
• Atomically sharp and clean interfaces were observed between Bi2SeO2 and its native oxide.
• Sufficiently large conduction band offsets (1.13 eV for holes, 1.55 eV for electrons) were determined for the semiconductor-oxide interface.

Conclusions:

• The combination of a high-κ native oxide, clean interfaces, and suitable band offsets makes 2D Bi2SeO2 a strong candidate for future transistor technologies.
• This material system addresses the limitations of traditional semiconductors at ultimate scaling limits.
• 2D Bi2SeO2 offers a promising pathway for advancing nanoelectronics beyond current silicon-based technologies.