2 research outputs found
High-Performance CVD Bernal-Stacked Bilayer Graphene Transistors for Amplifying and Mixing Signals at High Frequencies
Tunable
bandgap can be induced in Bernal-stacked bilayer graphene by a perpendicularly
electric displacement field. Here, we carry out a comprehensive study
on the material synthesis of CVD Bernal-stacked bilayer graphene and
devices for amplifying and mixing at high frequencies. The transistors
show large output current density with excellent current saturation
with high intrinsic voltage gain up to 77. Positive extrinsic forward
power gain |<i>S</i><sub>21</sub>|<sup>2</sup> has been
obtained up to 5.6 GHz as well as high conversion gain of −7
dB for the mixers. The conversion gain dependence on tunable on/off
ratio of the transistors has also been discussed
Effects of Nitrogen and Hydrogen Codoping on the Electrical Performance and Reliability of InGaZnO Thin-Film Transistors
Despite
intensive research on improvement in electrical performances of ZnO-based
thin-film transistors (TFTs), the instability issues have limited
their applications for complementary electronics. Herein, we have
investigated the effect of nitrogen and hydrogen (N/H) codoping on
the electrical performance and reliability of amorphous InGaZnO (α-IGZO)
TFTs. The performance and bias stress stability of α-IGZO device
were simultaneously improved by N/H plasma treatment with a high field-effect
mobility of 45.3 cm<sup>2</sup>/(V s) and small shifts of threshold
voltage (<i>V</i><sub>th</sub>). On the basis of X-ray photoelectron
spectroscopy analysis, the improved electrical performances of α-IGZO
TFT should be attributed to the appropriate amount of N/H codoping,
which could not only control the <i>V</i><sub>th</sub> and
carrier concentration efficiently, but also passivate the defects
such as oxygen vacancy due to the formation of stable Znî—¸N
and Nî—¸H bonds. Meanwhile, low-frequency noise analysis indicates
that the average trap density near the α-IGZO/SiO<sub>2</sub> interface is reduced by the nitrogen and hydrogen plasma treatment.
This method could provide a step toward the development of α-IGZO
TFTs for potential applications in next-generation high-definition
optoelectronic displays