Adsorption and dissociation of hydrazoic acid on Al(111)

Hydrazoic acid (N3H) is a possible precursor for the low-temperature growth of aluminum nitride (A1N), a wide-gap semiconductor with many potential ap plications. We have investigated the adsorption of N3H on the Al(111) surfa ce using ab initio density-functional theory and a self-consistent-charge d ensity-functional tight-binding method. This process may be seen as an init ial step of the heteroepitaxial growth of A1N. Our results show that the mo lecule dissociates on the surface into N-2 and a NH radical without encount ering a barrier. Furthermore, while the NH radical forms strong bonds with the top surface atoms, there is no significant binding between the N-2 frag ment and the surface. We display the complete dissociation path and the tot al energies associated with the different intermediate configurations and c ompare our results to experimental data.