High luminance carbon nanotube field emission cold cathode based on indium tin oxide/Ti composite electrode

Carbon nanotube (CNT) cathode with an indium tin oxide (ITO)/Ti composite electrode is successfully fabricated using both magnetron sputtering technology and screen-printed technology which can improve adhesive performance between electrode and CNT cathode of transplanted-type CNT cold cathode, thus eliminating the effects of interface barrier and non-ohmic contact on field emission uniformity and stability of CNT cathode. Microstrcture of ITO/Ti-based CNT cathode is studied by X-ray diffraction and field emission scanning electron microscopy. The results show that TiC phase forms in ITO/Ti-based CNT cathode, thereby a strong interaction system is created between CNT and Ti substrate which reduces, or even eliminates the interface barrier between electrode and CNT, and increases the probability of forming ohmic contact. The resistivity measurement by four probe technology shows that the ITO/Ti-based CNT cathode has performance of resistances in parallel and electric conductivity of CNT cathode increases. Characteristic test of ITO/Ti-based CNT cathode shows that field emission current reaches 384 μA/cm2 which significantly increases compared with that of ITO-based CNT cathode, and that the tested anode can be induced to emit stable, uniform and high luminance. So the ITO/Ti composite electrode is an effective way to make a CNT cathode with stable and uniform field emission and low power.