Stable field emission from screen-printed ZnO-tetrapod emitters

This article describes a study on field emission properties of ZnO tetrapods, which were synthesized by rapid heating metal zinc pellets at 900 °C in air. A diode configuration with a screen-printed cathode was used to measure the field emission properties of the ZnO emitters. A low turn-on field of 1.86 V/μm at a current density of 1 μA/cm² was obtained, while the emission current density reached 1 mA/cm² at an applied field of 4.15 V/μm and showed no saturation. The field emission of the ZnO-tetrapod sample was recorded for 20 h: no degradation of the emission current was observed in this period, while the fluctuations of the emission current were less than 3%. These experimental results indicate that ZnO tetrapods are a promising cold cathode for low cost field emission displays using screen printing.