Fabrication And Electrical Properties Of Printed Carbon Nanotubes Thin-film Transistor And Simple Logic Circuits

Printed electronics has been flourishing as an independent discipline, technology and industry in the last five years. Compared with conventional silicon-based microelectronics, printed electronics has some characteristics, such as large area, flexibility, low cost, and environment-friendliness, which make printed electronics have wide applications, including flexible batteries, flexible thin-film solar cells, thin film transistors (TFTs), light emitting diodes, and electronic paper. Printed thin film transistor is a basic unit of printed electronics. Its performance directly affects the performance of the printed electronics. Generally, the printing performance of the thin film transistor depends on the nature of the semiconductor material. To obtain high-performance printed thin film transistor, semiconductor material should have good solubility, good film forming capacity and good environmental stability. Semiconducting single-walled carbon nanotubes (s-SWCNTs) have been regarded as one of ideal semiconductor materials to prepare printable inks due to its excellent electrical, mechanical, optical properties, high stability and solubility in aqueous and solvents. However, the separation of semiconducting carbon nanotubes, uniformity of SWCNT TFTs and the precise placement and efficient deposition of s-SWCNTs on substrates are challenges for achieving printed high-performance SWCNT TFTs.In this paper, selectively sorted s-SWCNTs by poly [(9,9’-two-octyl-2,7-fluorene)-and-(1,4-benzo-2,10,3-thiadiazole)](PFO-BT) were studied in detailed. A rapid and efficient method has been developed. High-density SWCNT thin films and high-performance SWCNT TFTs were obtained on oxygen plasma treated rigid and flexible substrates. Mobility and on/off ratio of printed bottom-gate SWCNT TFTs on SiO2/Si are up to26.6cm2v-1s-1and106, respectively, and the flexible, printed TFTs also showed excellent electrical properties with mobility up to91.9cm2v-1S-1and on/off ratio up to105. Furthermore, printed logic circuits, such as inverters, ring oscillators, NAND and NOR, were also fabricated on both rigid and flexible substrates.