Development of Paper Transistor Using Carbon-Nanotube-Composite Paper
We have developed a unique “paper transistor” comprised of carbon nanotube (CNT) composite papers. CNTs have recently attracted much research attention in the nanotechnology field due to their many excellent physical properties, including good electrical and heat conductivities, physical strength, and dual semiconducting- and metallic- characteristics. CNTs have great potential for use as many different functional materials. In a previous work, we developed a CNT-composite paper as a new functional material. A normal paper is flexible and can be fabricated and used easily, and we can easily fabricate the CNT-composite paper by mixing pulp with CNTs. The resulting CNT-composite paper has both CNT and normal paper characteristics. In this study, we focused primarily on the dual semiconducting- and metallic- characteristics exhibited by CNTs because we can create paper composites that are both semiconducting and metallic. Our main goal was to develop a field-effect-transistor (FET) using semiconducting- and metallic- CNT-composite papers. A conventional FET has metal, insulator, and semiconductor layers. Our FET also has three layers: the metallic CNT-composite paper is used for gate, source, and drain electrodes as the metal layer; the semiconducting CNT-composite paper is used for a semiconductor as the channel layer; and the normal paper is used as a gate insulator layer. The key point here is that we were able to design and develop an FET using only normal paper and two kinds of CNT-composite paper, without any silicon or semiconductors. After the construction, we measured the electrical conductivity of our FET to test its operation. A drain-to-source current of about 10μA was observed. Moreover, we could control the current flow by controlling the gate voltage. These results demonstrate that it is possible to fabricate a paper FET using only normal paper and two kinds of CNT-composite paper.
Pietro Vincenzini and Cosimo Carfagna
Y. Kawamura et al., "Development of Paper Transistor Using Carbon-Nanotube-Composite Paper", Advances in Science and Technology, Vol. 80, pp. 59-64, 2013