title: Flexible logic circuits based on top-gate thin film transistors with printed semiconductor carbon nanotubes and top electrodes.
abstract: In this report printed thin film transistors and logic circuits on flexible substrates are reported. The top-gate thin film transistors were made of the sorted semiconducting single-walled carbon nanotubes (sc-SWCNTs) ink as channel material and printed silver lines as top electrodes and interconnect. 5 nm HfOx thin films pre-deposited on PET substrates by atomic layer deposition (ALD) act as the adhesion layers to significantly improve the immobilization efficiency of sc-SWCNTs and environmental stability. The immobilization mechanism was investigated in detail. The flexible partially-printed top-gate SWCNT TFTs display ambipolar characteristics with slightly strong p-type when using 50 nm HfO(x) thin films as dielectric layer, as well as the encapsulation layer by atomic layer deposition (ALD) at 120 °C. The hole mobility, on/off ratio and subthreshold swing (SS) are ∼ 46.2 cm(2) V(-1) s(-1), 10(5) and 109 mV per decade, respectively. Furthermore, partially-printed TFTs show small hysteresis, low operating voltage (2 V) and high stability in air. Flexible partially-printed inverters show good performance with voltage gain up to 33 with 1.25 V supply voltage, and can work at 10 kHz. The frequency of flexible partially-printed five-stage ring oscillators can reach 1.7 kHz at supply voltages of 2 V with per stage delay times of 58.8 μs. This work paves a way to achieve printed SWCNT advanced logic circuits and systems on flexible substrates.
authors.affiliation: Printable Electronics Research Centre, Suzhou Institute of Nanotech and nano-bionics, Chinese Academy of Sciences, No. 398 Ruoshui Road, Suzhou Industrial Park, Suzhou, Jiangsu Province 215123, PR China. jwzhao2011@sinano.ac.cn zcui2009@sinano.ac.cn.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Xu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Jianwen
authors.initials: J
authors.lastname: Zhao
authors.forename: Wenya
authors.initials: W
authors.lastname: Xu
authors.forename: Weibing
authors.initials: W
authors.lastname: Gu
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhang
authors.forename: Long
authors.initials: L
authors.lastname: Qian
authors.forename: Zheng
authors.initials: Z
authors.lastname: Cui