Low-voltage organic thin-film transistors with large transconductance

We have developed an organic thin-film transistor (TFT) technology that aims at providing a good balance of static and dynamic performance parameters. An inverted staggered (bottom-gate, top-contact) device structure with patterned metal gates, a room-temperature-deposited gate dielectric providing a capacitance of $0.7μF∕cm2$⁠, and vacuum-deposited pentacene as the semiconductor were employed. The TFTs have a channel length of $10μm$⁠, a carrier mobility of $0.4cm2∕Vs$⁠, an on/off current ratio of $107$⁠, a subthreshold swing of $100mV$/decade, and a transconductance per channel width of $40μS∕mm$⁠. Ring oscillators operate with supply voltages as low as $2V$ and with signal propagation delays as low as $200μs$ per stage.