CVD Cu2O and CuO Nanosystems Characterized by XPS

Abstract

In the present investigation, X-ray photoelectron and X-ray excited Auger electron spectroscopy analyses of the principal core levels (O 1s, Cu 2p, and Cu LMM) of Cu2O and CuO nanosystems are proposed. The samples were obtained by chemical vapor deposition starting from a novel second-generation copper(II) precursor, Cu(hfa)2·TMEDA (hfa=1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA=N,N,N′,N′-tetramethylethylenediamine), under a dry O2 atmosphere. The obtained route led to pure, homogeneous and single-phase Cu(I) and Cu(II) oxide nanosystems at temperatures of 300 and 500 °C, respectively, whose chemical nature could be conveniently distinguished by analyzing the Cu 2p band shape and position, as well as by evaluating the Auger parameters. The samples were characterized by O/Cu atomic ratios greater than the expected stoichiometric values, due to marked interactions with the outer atmosphere attributed to their high surface-to-volume ratio.