Abstract
The effects of MgO on nitrogen dissolution and p-type conduction of sol-gel Al-N codoped Mg x Zn 1-x O films were investigated. Substitution of MgO for ZnO significantly increased the solubility of nitrogen in the Mg x Zn 1-x O films. The formation energies of N O and (N 2 ) O were found to decrease with increasing MgO content, resulting in higher concentrations of N O and (N 2 ) O . The acceptor levels of N O were estimated to be about 114 and 163 meV above the valence band maximum, respectively, for x = 0 and x 0.05 films. The bandgap and the acceptor ionization energy increase with the MgO content, leading to a reduction in hole concentration and an increase in resistivity. The homojunction formed between a Al-N codoped Mg x Zn 1-x O and a n-type Ga 0.01 Zn 0.99 O film displayed a typical rectifying behavior with a turn-on voltage of 2V, confirming the p-type conduction of the Al-N codoped Mg x Zn 1-x O films. © 2011 The Electrochemical Society.