We have demonstrated tunable
n-channel fullerene and
p-channel pentacene OFETs and CMOS inverter circuit based on a bilayer-dielectric structure of CYTOP (poly(perfluoroalkenyl vinyl ether)) electret and SiO
2. For both OFET types, the
Vth can be electrically tuned thanks to the charge-trapping at the interface of CYTOP and SiO
2. The stability of the shifted
Vth was investigated through monitoring a change in transistor current. The measured transistor current versus time after programming fitted very well with a stretched-exponential distribution with a long time constant up to 10
6 s. For organic CMOS inverter, after applying the program gate voltages for
n-channel fullerene or
p-channel pentacene elements, the voltage transfer characteristics were shifted toward more positive values, resulting in a modulation of the noise margin. We realized that at a program gate voltage of 60 V for
p-channel OFET, the circuit switched at 4, 8 V, that is close to half supply voltage
VDD, leading to the maximum electrical noise immunity of the inverter circuit.
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