General aspects of the growth of copper nitride nanofilms

Conversion of copper into copper nitride at T = 293 K in copper nanofilms of thickness d = 2–13 nm has been studied by optical spectroscopy, optical microscopy, and gravimetry. Kinetic curves for the degree of conversion in the films are adequately represented by a linear, inverse logarithmic, cubic, or logarithmic rate law, depending on copper film thickness. We have measured the contact potential difference across the Cu and Cu3N films and the photovoltage in the Cu–Cu3N system, and constructed the energy band diagram of the Cu–Cu3N films. A model has been proposed for the chemical transformations in the Cu films, which includes ammonia adsorption, an equilibrium carrier diffusion and redistribution in the Cu–Cu3N interfacial field, and copper nitride formation.