Oxidation behaviour of copper nanofractals produced by soft-landing of size-selected nanoclusters

Abstract

We report the oxidation dynamics of a copper nanocluster assembled film, containing fractal islands, fabricated by the soft-landing of size-selected copper nanoclusters with an average diameter of 3 nm. The time evolution of the spontaneous oxidation of the prepared film in air at room temperature (RT) was studied. A compositional analysis of the film was carried out in an ultra-high vacuum (UHV) deposition chamber using an in situ X-ray photoelectron spectroscopy (XPS) system. The morphological aspects of the deposited film were studied with a high resolution scanning electron microscope (SEM) and an atomic force microscope (AFM). We report the spontaneous production of highly pure (∼95%) and technologically appealing nano-crystalline Cu₂O within 300 seconds of air exposure. The crystalline structure was probed using high resolution transmission electron microscopy (HRTEM) and the optical properties were studied using a cathodoluminescence (CL) device attached to a SEM.