Abstract
We report the fabrication of field emitter arrays (FEAs) of CNTs using self-assembly monolayer (SAM) technique at room temperature. Single-walled nanotubes (SWNTs) were cut into sub-micron length by sonication in a mixed solution of sulfuric acid and hydrogen peroxide. The edge sites of SWNTs were functionalized into carboxylic groups to link SAM on substrates. Substrates were prepared with a silicon wafer and a polymer film. The substrates were patterned into ordered circles for uniform and stable emission. The SWNTs were aligned at room temperature by dipping the patterned substrates into different solutions in series. The presence of aligned SWNTs was observed by an atomic force microscopy (AFM) and Raman spectroscopy. The field emission measurements with SWNT emitters showed that the turn-on field was 2.8 V/µm for the silicon wafer and 3.9 V/µm for the polymer film at the emission current density of 10 µA/cm2. The current density was 0.9 mA/cm2 and 1.6 mA/cm2 at 6.0 V/µm, respectively. The I-V curves agree well with the Fowler-Nordheim model, confirming that the emission currents are indeed from the cold electron emission. This room temperature process is suitable for the fabrication of flexible field emitter arrays.
