Thermal transformations in nanosized copper layers

The thermal treatment of copper films 3–168 nm thick over the temperature range 373–600 K for 1–120 min was shown to result in the formation of copper(I) oxide. Depending on the initial film thickness and temperature, the kinetic curves of the degree of transformation were satisfactorily described by a linear, inverse logarithmic, parabolic, or logarithmic law. Contact potential difference and photo-electromotive force measurements were used to suggest a model including the stages of oxygen adsorption, charge carrier redistribution in the Cu₂O-Cu contact field (negative on the side of Cu₂O), and copper(I) oxide formation.