Electronic and mechanical responses of two-dimensional HfS2, HfSe2, ZrS2, and ZrSe2 from first-principles

During the last decade, numerous high-quality two-dimensional (2D) materials with semiconducting electronic character have been synthesized. Recent experimental study (Sci. Adv. 2017;3: e1700481) nevertheless confirmed that 2D ZrSe₂ and HfSe₂ are among the best candidates to replace the silicon in nanoelectronics owing to their moderate band-gap. We accordingly conducted first-principles calculations to explore the mechanical and electronic responses of not only ZrSe₂ and HfSe₂, but also ZrS₂ and HfS₂ in their single-layer and free-standing form. We particularly studied the possibility of engineering of the electronic properties of these attractive 2D materials using the biaxial or uniaxial tensile loadings. The comprehensive insight provided concerning the intrinsic properties of HfS₂, HfSe₂, ZrS₂, and ZrSe₂ can be useful for their future applications in nanodevices.