Complementary Ring Oscillator Exclusively Prepared by Means of Gravure and Flexographic Printing

A complementary ring oscillator has been prepared using exclusively fast and continuous rotary printing methods, namely, gravure and flexographic printing, so that all layers were additively deposited and no additional patterning nor interconnecting step whatsoever was involved. This became possible due to the availability of a printable air-stable n-type organic semiconductor, i.e., a small molecule perylene derivative. Using the same dielectric for both types of transistors, the characteristics of the n-type transistors are reasonably similar to the ones of the p-type transistors, which are based on the previously used organic semiconductor 6,13-bis(triisopropylsilylethynyl) pentacene. The printed circuits are robust against variations of individual transistor parameters and significantly outperform comparable unipolar circuits in terms of all relevant properties. The superior performance can be attributed to complementary circuitry, the advantage of which is thereby demonstrated for the case of printed circuits.