Structural and electronic properties of two-dimensional (110) diamond nanofilms by first-principles calculations

Based on the first-principles calculations, we investigate the structural and electronic properties of pure and hydrogenated two-dimensional (2D) (110)-oriented diamond nanofilms related to the layer number (n). After structural optimization, for the pure (110) diamond nanofilms at n = 1 and 2, the original buckling 2D diamonds reconstruct into the planar graphene. For the pure 2D diamond films at n 3 and the cases of semi-hydrogenated and full-hydrogenated 2D diamond nanofilms, the original diamond structures are energetically favorable to be maintained. The calculated electronic properties of these optimized structures show that the pure and semi-hydrogenated 2D diamond nanofilms have metallic characteristics, and the full-hydrogenated structures are semiconductors. It theoretically demonstrates that the n and surface functionalization could effectively modulate the structural and electronic properties of the 2D atomically thick (110) diamond nanofilms, revealing their applications in numerous practical fields especially fabricating low-dimensional optoelectronic devices.