Extremely stable field emission from AlZnO nanowire arrays

Extremely stable electric field emission from well-aligned AlZnO nanowire arrays is realized. The emission current density is up to 6.5mA∕cm2, and no current saturation is observed. The turn-on field is 2.9V∕μm as d (distance between the nanowire emitters and anode) is 0.64mm. After aging for two days, the emission current is extremely stable with the fluctuations of±0.4%. The high stability arises from the high crystal quality with few surface states of the nanowires and the in situ fabrication of cathodes. The field emission behaviors are in excellent agreement with Fowler–Nordheim theory, and the relationship between the field enhancement factor β and d follows a universal equation. Our results imply that AlZnO nanowire arrays are promising candidates for field emission displays.