High-performance flexible hybrid field-effect transistors based on cellulose fiber paper

IEEE Electron Device Letters, VOL. 29, NO. 9,

Abstract—In this letter, we report for the first time the use of a sheet of cellulose-fiber-based paper as the dielectric layer used in oxide-based semiconductor thin-film field-effect transistors(FETs). In this new approach, we are using the cellulose–fiber-based paper in an “interstrate” structure since the device is built on both sides of the cellulose sheet. Such hybrid FETs present excellent operating characteristics such as high channel saturation mobility (> 30 cm2/Vs), drain–source current on/off modulation ratio of approximately 104, near-zero threshold voltage, enhancement n-type operation, and subthreshold gate voltage swing of 0.8 V/decade. The cellulose-fiber-based paper FETs’ characteristics have been measured in air ambient conditions and present good stability, after two months of being processed. The obtained results outpace those of amorphous Si thin-film transistors (TFTs) and rival with the same oxide-based TFTs produced on either glass or crystalline silicon substrates. The compatibility of these devices with large-scale/large-area deposition techniques and low–cost substrates as well as their very low operating bias delineates this as a promising approach to attain high-performance disposable electronics like paper displays, smart labels, smart packaging, RFID, and point-of-care systems for self-analysis in bioapplications, among others.

This work was supported in part by the Fundação para a Ciência e a Tecnologia (FCT), Ministério da Ciência, Tecnologia e Ensino Superior (MCTES), under Project PTDC/CTM/73943/2006 and Project PTDC/EEA-ELC/64975/2006 and in part by the Electronic and Telecommunications Research Institute (ETRI),Korea. The work of P. Barquinha was supported by FCT under Fellowship SFRH/BD/17970/2004. The work of G. Gonçalves was supported by FCT under Fellowship SFRH/BD/27313/2006.