Variation of structure and band gap for N doped Cu2O films deposited with ceramic target

Highlights: • With ceramic target, Cu₂O:N films were deposited at room temperature conveniently. • With the increase of nitrogen flow rate, the prefer orientation of Cu₂O films varied. • Inhibition of oxygen vacancy by using Cu₂O target may lead to the band gap narrowing. • Through N doping, the resistivity of Cu₂O films was reduced to 2.1 Ωcm. - Abstract: With ceramic target, N doped Cu₂O films were deposited by Radio-Frequency magnetron sputtering. The structural, optical and electrical properties were studied. Along with the increase of nitrogen flow rate, the preferred orientation of Cu₂O films varied from (111) plane to (200) plane. In addition, may be due to the inhibition of oxygen vacancy by using Cu₂O target, an obvious optical band gap narrowing was observed. Hall results indicated that the resistivity decreased sharply with the increase of carrier concentration. And the lowest value 2.1 Ωcm was obtained when the nitrogen flow rate was increased to 20 sccm. However, due to the defects which induced by N doping, the hall mobility is decreased slightly. X-ray photoelectron spectra results further demonstrated the formation of Cu₂O films without other phases.