Density-functional theory calculations of XH3-decorated sic nanotubes (X ={C, Si}) : Structures, energetics, and electronic structures

We have investigated the structures, energetics, and electronic structures of XH3-radical-decorated silicon carbide nanotubes (SiCNTs), where X={C,Si}, using density-functional theory. Our results show that all the XH3 radicals can be chemically adsorbed on Si sites or C sites on the tube wall, with the adsorption energies ranging from −2.01 to −2.90eV for a (5,5) SiCNT. The modification in electronic structures of these decorated SiCNTs highly depends on the adsorption site rather than the XH3 species. The electronic structures of XH3-decorated SiCNTs demonstrate characteristics of n-type semiconductors for XH3 adsorbed on a C atom, whereas p-type semiconductors can be achieved by XH3 adsorption on a Si atom.