Exploring electronic characteristics of bilayer HfS2 under mechanical strain and external electric field: A first-principles approach

Abstract

This study employed the density functional theory (DFT) to explore the dynamic stability of different stacking configurations of bilayer HfS2 (2L-HfS2) and the influence of external conditions on its electronic properties. These results indicate that the AA configuration is the most stable among the various stacking configurations. Calculations of the carrier effective mass revealed that the artificially stacked 2L-HfS2 maintained a small effective mass of electrons and holes and exhibited high carrier mobility. Further investigation revealed diverse trends in the electronic properties of 2L-HfS2 under vertical strain, in-plane strain, shear strain, and an applied external electric field. These variations encompass bandgap size alterations, band structure evolution, and transitions in the metallic behavior. This systematic study elucidates the regulatory effects of different strains and external electric field conditions on the electronic properties of 2L-HfS2, thereby providing a vital theoretical foundation and experimental guidance for its application in electronics and optoelectronics.