Fully Solution Processed Bottom-Gate Organic Field-Effect Transistor With Steep Subthreshold Swing Approaching the Theoretical Limit

This letter realizes both large gate dielectric capacitance and reduced sub-gap density of states at the channel in the same organic field effect transistor (OFET) structure by adopting optimized low-k/high-k bilayer gate dielectric. Subthreshold swing (SS) as small as 64 mV dec
^-1
can be achieved with a thick (>360 nm) gate dielectric layer. This is the smallest SS value reported so far for all reported low voltage OFETs, and is even comparable with that of 22 nm technology node Si-FETs. The device can thus be switched within a very small voltage swing of 0.8 V, while having an ON/OFF ratio larger than 105. The device also shows excellent operational and storage stabilities.