Adsorption and evolution behavior of 4C1Si island configurations on diamond (001) surface: A first principle study

The adsorption energy of the 4C1Si island configurations and the diffusion activation energies of carbon and silicon atoms on diamond (001) surface were calculated with first principle method based on density functional theory (DFT) to study the growth of diamond films and the growth position of silicon particles after they are mixed into the composite film. The 4C1Si island configurations consist of five types of C-by-3C1Si configurations and four types of Si-by-4C configurations. The adsorption energy and total energy of the 4C1Si island configurations were calculated firstly. In addition, the diffusion activation energies of the carbon and silicon atoms were calculated. The results show that: (1) the adsorption energy of the Si-by-4C island configurations is higher than that of the C-by-3C1Si island configurations. This indicates that it is not easy for silicon atoms to remain stable in the 3C1Si island. In contrast, silicon atoms are easy to move out of the island so that the carbon atoms out of the 3C1Si Island can enter the island to form the 4C island; (2) Compared with the carbon atom, silicon atom needs lower diffusion activation energy to move into or out of the island. This shows that silicon atoms are more active than carbon atoms. Thus, it is easier for silicon particles to fill the vacancy defects in diamond/Si films, improving the compactness of the diamond composite films. (C) 2014 Elsevier B.V. All rights reserved.