Nano patterning and fabrication of single polypyrrole nanowires by electron beam lithography

In this paper, fabrication of nanostructures of conducting polypyrrole (PPy) thin films on the surfaces by in situ chemical polymerization in the presence of different anionic dopants including anthraquinone-2-sulfonic acid sodium salt monohydrate/5-sulfosalicylic acid dehydrate (AQSANa/SSCA) and camphor sulfonic acid (CSA) is reported. Lift-off process combined with electron beam lithography (EBL) is used for fabrication of nano patterns of conducting PPy thin films down to 100 nm. In addition, the ability to create ordered single PPy nanowires of controlled dimension, with very high aspect ratio, and dendrite free features between Au electrodes for fabricating of field effect transistor (FET) was demonstrated by single wires of PPy-CSA and PPy(AQSANa,SSCA) with 250 nm widths, up to 12 pm lengths and 100 nm thickness. I-V measurements of both single PPy-CSA ((similar to)124 S/cm) and PPy-(AQSANa,SSCA) ((similar to)5 S/cm) nanowires indicated Ohmic or space charge limited conduction, depending on the applied bias on the contact electrodes. A considerable modulation in the electrical conductivity of PPy-CSA and PPy-(AQSANa,SSCA) nanowire p-FETs was demonstrated as a result of varying the gate potential. Both PPy-CSA and PPy-(AQSANa,SSCA) nanowire p-FETs provide good performance transistors, nevertheless show different device electrical characteristics due to used different anionic dopants.