Deposition of nanocrystalline copper oxide films for solar cell application

Nanocrystalline copper oxide films have been synthesized on glass 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) was observed at the deposition condition of DC power 150 W, pressure 3.3 Pa, substrate temperature 200degC, Argon flow rate 10 seem and O₂ flow rate 1 sccm. With increasing the oxygen flow rate to 3 - 5 and 7 sccm, CuO (-111) could be obtained at 100 and 200degC, respectively. 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 50-200degC show that only (-111) plane is obtained. The SEM pictures show that the grain size increases with the deposition increases.