High-Speed, Inkjet-Printed Carbon Nanotube/Zinc Tin Oxide Hybrid Complementary Ring Oscillators

The materials combination of inkjet-printed single-walled carbon nanotubes (SWCNTs) and zinc tin oxide (ZTO) is very promising for large-area thin-film electronics. We compare the characteristics of conventional complementary inverters and ring oscillators measured in air (with SWCNT p-channel field effect transistors (FETs) and ZTO n-channel FETs) with those of ambipolar inverters and ring oscillators comprised of bilayer SWCNT/ZTO FETs. This is the first such comparison between the performance characteristics of ambipolar and conventional inverters and ring oscillators. The measured signal delay per stage of 140 ns for complementary ring oscillators is the fastest for any ring oscillator circuit with printed semiconductors to date.