Ab Initio Investigation of the Hydrogen Interaction on Two Dimensional Silicon Carbide

A series of density functional theory calculations were performed to understand the bonding and interaction of hydrogen adsorption on two-dimensional silicon carbide obtained from molecular dynamics simulation. The converged energy results pointed out that the H atom can sufficiently bond to 2D SiC at the top sites (atop Si and C), of which the most stable adsorption site is T_Si. The vibrational properties along with the zero-point energy were incorporated into the energy calculations to further understand the phonon effect of the adsorbed H. Most of the 2D SiC structure deformations caused by the H atoms were found at the adsorbent atom along the vertical axis. For the first time, five SiC defect formations, including the quadrilateral-octagon linear defect (8-4), the silicon interstitial defect, the divacancy (4-10-4) defect, the divacancy (8-4-4-8) defect, and the divacancy (4-8-8-4) defect, were investigated and compared with previous 2D defect studies. The linear defect (8-4) has the lowest formation energy and is most likely to be formed for SiC materials. Furthermore, hydrogen atoms adsorb more readily on the defect surface than on the pristine SiC surface.