Local chemical states and thermal stabilities of nitrogen dopants in ZnO film studied by temperature-dependent x-ray photoelectron spectroscopy

Local chemical states and thermal stabilities of N dopants in ZnO-N film are investigated by temperature-dependent x-ray photoelectron spectroscopy. Different types of N local states are detected, including N(2) Molecules occupying O sites [(N(2))(O)], -NO species, substitutional N atoms in O- and N-rich local environments (alpha- and beta-N(O)). Compared to the beta-N(O), the alpha-N(O) shows a better thermal stability up to 723 K. However, the transformation from alpha-N(O) acceptor 10 undesirable (N(2))(O) donor occurs above 743 K. The variation of N local states also affects Zn and O binding energies. Photoluminescence studies indicate the shallow acceptor nature of alpha-N(O). (C) 2009 American Institute of Physics. [doi 10.1063/1.3259644]