Dark current versus voltage of the ZnO nanowire. In air (unfilled squares) and in vacuum (filled squares). The measurement was performed after the device was kept in the dark for several days. Inset: SEM image of the device. The diameter of the wire is approximately 110 nm, and the gap between the electrodes in test is approximately1.8 μm.
Bao et al. Nanoscale Research Letters 2011 6:404 doi:10.1186/1556-276X-6-404