In-N codoped ZnMgO films have been prepared on glass substrates by direct current reactive magnetron sputtering. The p-type conduction could be obtained in ZnMgO films by adjusting the N2O partial pressures. The lowest resistivity was found to be 4.6 Omega cm for the p-type ZnMgO film deposited under an optimized N2O partial pressure of 2.3 mTorr, with a Hall mobility of 1.4 cm(2)/V s and a hole concentration of 9.6 x 10(17) cm(-3) at room temperature. The films were of good crystal quality with a high c-axis orientation of wurtzite ZnO structure. The presence of In-N bonds was identified by X-ray photoelectron spectroscopy, which may enhance the nitrogen incorporation and respond for the realization of good p-type behavior in In-N codoped ZnMgO films. Furthermore, the ZnMgO-based p-n homojunction was fabricated by deposition of an In-doped n-type ZnMgO layer on an In-N codoped p-type ZnMgO layer. The p-n homostructural diode exhibits electrical rectification behavior of a typical p-n junction. (c) 2009 Elsevier B.V. All rights reserved.