Pulsed voltage driving enhanced electron emission in ZnO nanowire cold cathode flat-panel X-ray source.

A fully vacuum-sealed flat-panel X-ray source was fabricated composed of molybdenum metal anode and ZnO nanowire field emitters array cathode. The cathode current and X-ray radiation dose rate of the device were measured when the anode is applied with direct current (DC) and pulsed voltage, respectively. It is found that the peak emission current and corresponding dose rate under pulsed voltage driving are much higher than those under DC voltage driving. The phenomena may be explained by a plasma induced field emission enhancement related to the electron bombardment induced gas desorption. Clear projection X-ray imaging of moving objects was obtained using pulsed voltage driving. The result shows that owing to the enhanced emission current driven by the pulsed voltage, the flat-panel X-ray source can achieve fast and clear imaging of high-speed moving objects. Our results are of significance for the application of large area flat-panel X-ray source in dynamic imaging. • Fully vacuum-sealed diode-structure flat-panel X-ray source was fabricated using ZnO nanowire field emitters arrays. • Peak emission current and dose rate under pulsed voltage driving are observed to be higher than that under DC voltage. • The enhanced emission current was explained by plasma induced emission enhancement. • Clear imaging of high-speed moving objects was achieved using the pulsed voltage driving flat-panel X-ray source. [ABSTRACT FROM AUTHOR]