Field-effect transistors based on single nanowires of conducting polymers

Field-effect transistors based on single nanowires of conducting polymers (i.e., polyaniline and polypyrrole) were fabricated and characterized. The 100-nm-wide and 2.5-mu m-long conducting polymer nanowire field-effect transistors were turned "on" and "off" by electrical or chemical signals. A large modulation in the electrical conductivity of up to 3 orders of magnitude was demonstrated as a result of varying the electrochemical gate potential of these nanowires. Single nanowire conducting polymer field-effect transistors show higher electrical performance than field-effect transistors based on conducting polymer nanowire electrode junctions and thin films in terms of their transconductance (g(m)) and on/off current (I-on/I-off) ratio. Furthermore, the performance of single nanowires conducting polymer field-effect transistors was found to be comparable to the silicon nanowire field-effect transistors. These results imply that it is possible to tune the sensitivities of these conducting polymer nanowires by simple control of the electrolyte/liquid ion gate potentials. On the basis of these findings, we demonstrated the ability to tailor the sensitivities of sensors based on single conducting polymer nanowires.