Vertically stacked complementary inverters with solution-processed organic semiconductors

We report on vertically stacked complementary inverters implemented with a solution-processed [6,6]-phenyl c 61 butyric acid methyl ester (PCBM) n -channel thin-film transistor (TFT) fabricated on top of a 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) and poly(triarylamine) (PTAA) blend p -channel TFT. With a shared common gate electrode positioned between two dielectric layers, bottom-contact p - and top-contact n -channel TFTs showed saturation mobility values of 0.25 and 0.004 cm 2 /V s and threshold voltages of −3.9, and 0.3 V, respectively. The inverter yielded a gain value of −24 V/V with a switching threshold voltage value of 3.3 V at a supply voltage of 7 V. This demonstration of the use of solution-processed semiconductors in a vertically stacked complementary inverter geometry is a step forward towards the development of low-cost complementary electronics.