Enhanced Field Emission from ZnO Nanowire FEAs by Magnetron-Sputtered TiN Coating for Flat-Panel X-ray Source Application

Large-area zinc oxide (ZnO) nanowire field emitter arrays (FEAs) are critical for developing flat-panel X-ray sources for medical imaging and radiotherapy applications. In this study, titanium nitride (TiN) coated ZnO nanowire field emitter arrays (FEAs) with an area of 4.8×4.8 cm² were prepared. The TiN layer was deposited on the ZnO nanowires via direct-current magnetron sputtering. The 5-nm thickness TiN coating significantly improved the maximum field emission current of the FEAs from 1.25 mA to 2.5 mA. A flat-panel X-ray source was fabricated by integrating the TiN-coated ZnO FEAs with a Mo transmission anode and distinct X-ray imaging was obtained.