Formation of CuO on thermal and laser-induced oxidation of Cu<inf>3</inf>N thin films prepared by modified activated reactive evaporation

Copper oxide (CuO) thin films were prepared by direct oxidation of modified activated reactive evaporated copper nitride (Cu3N) thin films in air ambience. When annealed in air at higher temperatures, Cu3N films undergo complete decomposition and the residual Cu gets easily bonded with the atmospheric oxygen to form CuO. Annealing provides required activation energy for the formation of CuO. The formation of fairly crystallized CuO was confirmed by X-ray diffraction and Raman spectroscopy studies. However, the crystallite size of CuO films is smaller than their corresponding Cu3N phase. The surface morphology of the CuO films obtained through this method shows grains of non-uniform size distribution. Furthermore, Raman spectra on the as-grown Cu3N films were taken by varying the laser power. At higher laser power, microscopic CuO dots are formed due to laser-induced oxidation. It is proposed that p-type CuO can be easily grown over suitably prepared n-type Cu3N by local heating or laser irradiation in air.