Hybrid fabrication of flexible fully printed carbon nanotube field-effect transistors

A facile and cost-efficient multiple fully printed method to fabricate p-type carbon nanotube field-effect transistor (CNTFET) on the flexible paper substrate is proposed in this paper. Through the selective separation of polymer poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-(benzo [2,1,3] thiadiazol-4,7-diyl)] (PFO-BT) and stable dispersion of sodium dodecylbenzene sulfonate (SDBS) surfactant, the obtained CNTs individually dispersed ink (denoted as mono-dispersion ink) is applied in standard inkjet printers. The multiple system of Roll-to-Roll (R2R) flexo printing (to print silver-based catalyst ink for the subsequent electroless copper plating process) and inkjet printing (to print semiconductor channel material) is adopted in p-type metal-oxide-semiconductor field-effect transistor (MOSFET) fabrication with good printing line accuracy and high-throughput. The transistors obtained by this fabrication process can maintain an on-off ratio (I-on/I-off approximate to 2806), with approximately 70% of the devices' on-off ratio is concentrated in 10(3)-10(4) with a threshold voltage of about + 3 V. The flexible and fully printed strategy presented in this paper has a strong migration ability, which can be applied to a variety of semiconductor channel materials with diverse flexible substrates (e.g., polyimide, polyethylene terephthalate, etc.) and provide an effective and facile route for large-scale preparation of flexible integrated electronic devices.

Automated summary

This paper proposes a facile and cost-efficient fully printed method to fabricate p-type carbon nanotube field-effect transistor (CNTFET) on a flexible paper substrate. The method utilizes selective separation of polymer and stable dispersion of surfactant to create a mono-dispersion ink, which is applied using standard inkjet printers. The fabrication process combines roll-to-roll flexo printing and inkjet printing, resulting in high printing line accuracy and throughput. The fabricated transistors exhibit high on-off ratio and stable threshold voltage. This flexible and fully printed strategy provides a versatile approach for large-scale preparation of flexible integrated electronic devices.