Formation of p-type ZnMgO thin films by In–N codoping method

Abstract

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 N 2O partial pressures. The lowest resistivity was found to be 4.6 Ω cm for the p-type ZnMgO film deposited under an optimized N 2O partial pressure of 2.3 mTorr, with a Hall mobility of 1.4 cm 2/V s and a hole concentration of 9.6 × 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.