Facile collisional dissociation of N2 on a Si(111)-7x7 surface at room temperature

We demonstrate that the strong N2 bond can be efficiently dissociated at low pressure and ambient temperature on a Si(111)-7x7 surface. The reaction was experimentally investigated by scanning tunnelling microscopy and X-ray photoemission spectroscopy. Experimental and density functional theory results suggest that relatively low thermal energy collision of N2 with the surface can facilitate electron transfer from the Si(111)-7x7 surface to the p*-antibonding orbitals of N2 that significantly weaken the N2 bond. This facile N2 triple bond dissociation on the surface leads to the formation of a Si3N interface.