Two-dimensional Bi ₂ SeO ₂ and Its Native Insulators for Next-Generation Nanoelectronics

High Resolution Image Download MS PowerPoint Slide Silicon’s dominance in integrated circuits is largely due to its stable native oxide, SiO 2, known for its insulating properties and excellent interface to the Si channel. However, silicon-based FETs face significant challenges when further scaled, which inspires the search for better semiconductors. While 2D materials such as MoS 2, WSe 2, BP, and InSe are promising, they lack a stable and compatible native oxide. High mobility (812 cm 2 V –1 s –1 ) 2D Bi 2 SeO 2 stands out in this regard, as it can be oxidized into different forms of Bi 2 SeO 5, thereby forming compatible high-κ native oxides. Despite growing interest in this material system, a comprehensive understanding of its fundamental properties is lacking. This study uses density functional theory and molecular dynamics simulations to investigate the intrinsic properties of Bi 2 SeO 2, its native oxides, and its interfaces. Additionally, scanning transmission electron microscopy is employed to complement these theoretical analyses, providing detailed insights into the atomic-scale structure and interfaces of these materials. Building on these findings, we model semiconductor-oxide heterostructures and extract their intrinsic properties. Our results demonstrate that the atomically sharp and clean interface between oxide and semiconductor, the high dielectric constant (>30) of the oxide, and the sufficiently large conduction band offsets between the semiconductor and the most relevant β-phase of its native insulator (1.13 eV for holes and 1.55 eV for electrons) make this material system a strong candidate for future transistor technologies. These properties mitigate the limitations of traditional semiconductors and enhance device performance at the ultimate scaling limit, positioning 2D Bi 2 SeO 2 as a suitable choice for next-generation nanoelectronics.