Low resistivity phase-pure n-type Cu2O films realized via post-deposition nitrogen plasma treatment

Cu2O films were deposited on the sapphire substrates by pulsed laser deposition. The effects of nitrogen plasma treatment on the properties of the Cu2O films were studied. A phase transition from pure Cu2O to mixture of Cu2O and Cu and a change from p to n-type conduction were observed after the films being treated for different durations. The optical band gap of the films varied from 2.51 to 2.56 eV. Phase-pure n-type Cu2O film having a very smooth surface, a low resistivity of 20.50 Ω cm and a moderate Hall mobility of 3.76 cm2·v−1·s−1 was obtained for the 10 min plasma treated sample. The n-type conduction mechanism was discussed and clarified.