Field electron emission from inkjet-printed carbon black

We demonstrate the field electron emission from a carbon black dot array prepared by inkjet printing. A commercially available inkjet printer and drawing software were used to pattern the carbon-black-containing ink on the tungsten silicide surface which was deposited on a Si wafer. Field electron emission characteristics were measured using a diode configuration. It was found that oxygen reactive ion etching (RIE) of the printed carbon black is effective for obtaining the field emission. The turn-on voltage was 500 V and an emission current over 100 muA was obtained at a voltage of 1400 V with a 25 mum-wide gap between anode and cathode. It was also found that a rapid increase of the voltage is effective in increasing the emission current and the number of emission sites.