Nitrogen chemical state in N-doped Cu2O thin films

Nitrogen-doped Cu2O thin films have been deposited at room temperature by reactive magnetron sputtering. It is demonstrated that nitrogen doping in Cu2O can significantly improve the electrical properties by increasing the carrier concentration. The nitrogen chemical state in doped thin films has been investigated by electron energy loss spectroscopy, which reveals that nitrogen is in the form of molecular N2 in Cu2O thin films rather than the N-anion. Such experimental results are well consistent with the recently reported calculation, suggesting that in N-doped Cu2O, nitrogen mainly substitutes Cu in the molecular form, (N2)Cu, rather than in the atomic form at the oxygen site (NO).