SiC/Hf2CO2 vdWs heterojunction: Type-II narrow-bandgap heterojunction with excellent carrier mobility and photogalvanic effect

Abstract

In this work, the first-principles calculations were employed to systematically examine the structure, electronic and optical properties of the SiC/Hf₂CO₂ van der Waals heterojunction. Our calculations demonstrate that the heterojunction forms a type-II S-scheme structure with a direct bandgap of 1.25 eV, exhibiting strong redox capability. Carrier mobility calculations exhibit strong conductivity along the armchair direction, with the electron mobility of 2.57 × 10⁴ cm²/Vs. The heterojunction enhances ultraviolet absorption and extends absorption into the visible range, overcoming the spectral limitations of 2D SiC. The maximum photocurrent was calculated at the photon energy of 3.0 eV, confirming its visible light detection capability. These results indicate that SiC/Hf₂CO₂ heterojunction exhibits significant potential in self-powered photodetector.