AVS 54th International Symposium | |
Applied Surface Science | Tuesday Sessions |
Session AS-TuP |
Session: | Aspects of Applied Surface Science Poster Session |
Presenter: | W.H. Han, Myongji University, Korea |
Authors: | W.H. Han, Myongji University, Korea T.Y. Park, Myongji University, Korea C.J. Kang, Myongji University, Korea Y.S. Kim, Myongji University, Korea J.W. Kim, Myongji University, Korea Y.J. Choi, Myongji University, Korea |
Correspondent: | Click to Email |
The spatial uniformity and durability of field emission is one of the main issues in the carbon nanotube (CNT) field emission devices fabricated by a screen printing process. In this paper, we propose novel method to visualize field emission sites of CNT films two-dimensionally by adopting scanning probe microscopy technique and verify the conditions where the field emission of CNT emitters is spatially uniform and durable. While the anode probe with a small tip diameter of <100nm was scanned over CNT emitter surface whose dimension is 200um*200um, the field emission current was recorded through Keithley 6517A, converted into 256 grayscale level and displayed on monitor through LabView program. The anode probe was made by electro-chemically etching tungsten wire and the CNT emitter sample was fabricated by screen printing multiwall CNT whose diameter is 4-6nm and length is 1-2um on the indium-tin-oxide (ITO) glass. During scanning, the gap between W anode and ITO glass surface was maintained to be few tens of um. For the large scale imaging, we used the inertial nano positioner whose model number is ANPxyz100 made by Attocube Systems as a long range scanner. With this system, we could not only measure the emission turn-on field at fixed locations but also obtain the electron emission current map over large surface areas under constant anode voltage. We will discuss the relation between the local geometry and field emission properties of CNT emitter, and the fabrication condition of CNT emitters where the field emission is uniform and stable.