  In the path toward the integration of organic field effect transistors
(OFETs) and logic circuits into low-cost and mass produced consumer products,
all-organic devices based on printed semiconductors are one of the best options
to meet stringent costs requirements. Within this framework, it is still
challenging to achieve low voltage operation, as required by the use of thin
film batteries and energy harvesters, for which a high capacitance and reliable
organic dielectric is required. Here, the development of a parylene-C based
dielectric bilayer compatible with top-gate architectures for low-voltage OFETs
and logic circuits is presented. The polymer bilayer dielectric allowed the
high yield fabrication of all-polymer, bendable, transparent p- and n-type
OFETs operating below 2 V, with low leakage, uniform performances and high
yield. Such result is a key enabler for the reliable realization of
complementary logic circuits that can operate already at a voltage bias of 2 V,
such as well-balanced inverters, ring-oscillators and D-Flip-Flops.
