Dual Threshold Voltage Integrated Organic Technology for Ultralow-power Circuits

Abstract

For the first time, we demonstrate control of organic thinfilm transistor's (OTFT) threshold voltage (V [subscript T]) by modifying the gate work function. We present a near-room-temperature, fully lithographic process to fabricate integrated pentacene dual V [subscript T] OTFTs suitable for large-area and flexible mixed signal circuits. Platinum and aluminum are used as the gate metals for the high V [subscript T] (more depletion-like) and low V [subscript T] (more enhancement-like) p-channel devices, respectively. The availability of a high V [subscript 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 [subscript T] implementation, the dual V [subscript T] inverter occupies an area that is 30Ã Â smaller, and is 17Ã Â faster. These results show that p-channel only organic technologies can produce functional and low-power circuits without integrating a complementary device.