Organic CMOS Technology Based on Interface Doped Pentacene

An organic complementary-metal-oxide-semiconductor (CMOS) inverter based on pentacene acting as both n- and p-type organic semiconductor is presented. The circuit consists of two spatially separated transistors which are realized within one continuous pentacene layer. Both transistors act exclusively in unipolar mode with electron and hole mobilities of 0.11 cm2V-1s-1 and 0.10 cm2V-1s-1, respectively. In the domain of the n-channel, electron accumulation in the pentacene is enabled by deposition of traces of calcium acting as electron donator. The CMOS inverter works reliably within the range of the supply voltage (60 V) with a gain in between 17 and 24 which is among the highest values observed in organic systems. Nevertheless, the circuit shows hysteresis, which is explained by a gate voltage depending trap occupation in the n-channel.