Defective HfS2 nanoribbons: the influence of vacancy defects and different atoms at the edge on this material with the first principle calculations

Recently, various outstanding two-dimensional (2D) semiconductors have been studied. Some experimental and theoretical research works reveal that 2D-HfS2 can be a good candidate to substitute with the silicon in nanoelectronics due to its acceptable band gap. First, the influence of different edge atoms i.e. H (hydrogen) and O (oxygen) on two zigzag and armchair HfS2 nanoribbons is investigated with the first principle calculations.  Second, various types of vacancy defects such as 1Hf, 2Hf, 1S, 2S-1, 2S-2, 2S-3, 3S-1, 3S-2, 6S, and 1Hf+1S are applied to the pristine zigzag and armchair nanoribbon structures to investigate their electronic and transport behaviors changes. The calculated results reveal that all edge passivated structures are stable while the edge passivated structures with hydrogen atoms are more energy favorable. Moreover, some zigzag defective structures behave as metal while the armchair ones are semiconductor. The electronic property of HfS2 material is promising for its future applications in nanoelectronics.