Hydrogen and oxygen on InP nanowire surfaces

Recently great progress have been obtained with nanowires for electrical and optical applications. Due to the large surface-to-volume ratio of these nanostructures, of particular interest is the understanding of the unknown and hard to determine experimentally surface structure and the electronic effects due to surface states. In this letter the author investigate the structural and electronic properties of hydrogen passivation and the oxidation of surface InP nanowires by ab initio density functional theory. Our calculations show that hydrogen passivation is a chemisorbed process that removes the surface states, opening up the band gap. Our results for oxygen adsorbed on the hydrogen passivated InP nanowires show that there are many configurations where the oxygens are chemisorbed processes. The oxygens introduce energy levels back inside the band gap that can work as nonradiative recombination centers and can explain some experiments, such as the low luminescence observed in InP nanostructures. (c) 2006 American Institute of Physics.