Dual threshold voltage integrated organic technology for ultralow-power circuits

For the first time, we demonstrate control of organic thinfilm transistor´s (OTFT) threshold voltage (V_T) by modifying the gate work function. We present a near-room-temperature, fully lithographic process to fabricate integrated pentacene dual V_T OTFTs suitable for large-area and flexible mixed signal circuits. Platinum and aluminum are used as the gate metals for the high V_T (more depletion-like) and low V_T (more enhancement-like) p-channel devices, respectively. The availability of a high V_T device enables area-efficient zero-VGS current source loads. We demonstrate positive noise margin inverters which use pico Watts of power and a 3 V supply. Compared to a single V_T implementation, the dual V_T inverter occupies an area that is 30? smaller, and is 17? faster. These results show that p-channel only organic technologies can produce functional and low-power circuits without integrating a complementary device.