Band offsets rules between inorganic molecular crystal α-Sb₂O₃ and two-dimensional semiconductor materials for nanoelectronic applications

Abstract

The pursuit of high-performance, miniaturized electronics has spurred the exploration of two-dimensional semiconductor materials (2DSMs) for various device applications. While inorganic molecular crystal α-Sb₂O₃ shows promise as a van der Waals (vdW) dielectric or insulating substrate to enhance 2DSMs-based device performance, its moderate bandgap limits its broader use. To address this limitation, we perform a comprehensive first-principles study on the interfacial interaction and its impact on the band alignment between α-Sb₂O₃ and common 2DSMs, establishing selection rules of band offsets (BOs) for optimal device performance. Our key findings show that moderate band offsets (m-BOs), with both conduction band offset (CBO) and valence band offset (VBO) exceeding 0.5 eV, are crucial for preserving the intrinsic electronic properties of 2DSMs by significantly reducing interfacial interactions between α-Sb₂O₃ and 2DSMs. Furthermore, we establish the other layer-dependent selection rule of BOs, enabling the identification of 18, 57, and 81 2DSMs as 2D channels allowing three, four, and five α-Sb₂O₃ layers to function as outstanding vdW dielectrics. Our work offers valuable insights for designing and optimizing advanced nanoelectronic devices based on few-layer α-Sb₂O₃ and its suiTable 2DSM counterparts.