Optical and structural properties of nanocrystalline copper oxide thin films prepared by activated reactive evaporation

Nanocrystalline Cu2O thin films have been synthesized using an activated re active evaporation technique. Structural and optical characterizations of t hese films have been carried out using: glancing angle X-ray diffractometer ; Fourier transform infrared spectrometer; transmission electron microscope ; and LTV-VIS-NIR spectrophotometer. The nanocrystallite size in these film s was varied by varying deposition parameters. Optical studies show a direc t allowed transition and a shift in the optical absorption edge from the bu lk value with nanocrystallite size and stoichiometry of these films. These results show that single phase nanocrystalline Cu2O thin films can be synth esized at a relatively low substrate temperature using the activated reacti ve evaporation technique. These studies indicate that nanocrystallinity res ults in the stability of cubic Cu2O phase in these films. (C) 2001 Elsevier Science B.V. All rights reserved.