Enhancement of field emission of the ZnO film by the reduced work function and the increased conductivity via hydrogen plasma treatment

The ZnO films deposited by magnetron sputtering were treated by H/O plasma. It is found that the field emission (FE) characteristics of the ZnO film are considerably improved after H-plasma treatment and slightly deteriorated after O-plasma treatment. The improvement of FE characteristics is attributed to the reduced work function and the increased conductivity of the ZnO H films. Conductive atomic force microscopy was employed to investigate the effect of the plasma treatment on the nanoscale conductivity of ZnO, these findings correlate well with the FE data and facilitate a clearer description of electron emission from the ZnO H films.

National Natural Science Foundation of China 50601025 60876031"863" project of China 2009AA03Z305 Postgraduate Research, Innovation and Practice This work was financially supported by the National Natural Science Foundation of China (50601025 and 60876031) and the "863" project of China (2009AA03Z305). J. B. You thanks the CAS Special Grant for Postgraduate Research, Innovation and Practice.