p -type ZnO films by monodoping of nitrogen and ZnO-based p–n homojunctions

Abstract

Nitrogen-doped p-type ZnO (ZnO:N) films have been achieved by ultrasonic spray pyrolysis at atmosphere. The high structural quality of the obtained films was confirmed by x-ray diffraction, scanning electron microscopy, and photoluminescence spectra. Hall-effect and Seebeck-effect measurements indicate that the obtained p-type ZnO film shows a low resistivity of 3.02×10−2Ωcm, high carrier concentration of 8.59×1018cm−3, high mobility of 24.1cm2∕Vs, and high Seebeck coefficient of 408.2μV∕K at room temperature. Furthermore, the two-layer structured ZnO p–n homojunctions were prepared by depositing n-type ZnO layer on p-type ZnO:N layer. The current–voltage curve derived from the two-layer structure clearly shows the typical rectifying characteristic of p–n junctions.