Copper oxide, a direct band gap semiconductor with band gap about 1.21-1.51 eV, has been
regarded as a promising material for photovoltaic. Nanocrystalline copper oxide films have been
synthesized on Si by dc sputtering method. The effects of oxygen flow rate and deposition
temperature on the microstructure of nanocrystalline copper oxide films were investigated. X-ray
diffraction analysis shows that a broaden peak of Cu2O (111) at 36.720 was observed at the deposition
condition of DC power 150 W, pressure 2*10-2 Torr, substrate temperature 100 °C, Ar flow rate 15
sccm and O2 flow rate 1sccm. With increasing the oxygen flow rate to 3 and 5 sccm, CuO (-111) could
be observed at 36.58o. The increase of oxygen flow rate resulted in the film formation from Cu2O to
CuO. SEM pictures show that copper oxide films exhibit nanosize grains. X-ray diffraction patterns
of CuO films deposited at 50~200 °C show that only (-111) plane is obtained. The SEM pictures show
that the grain size increases with the deposition increases.
