DC characterization and fast small-signal parameter extraction of organic thin film transistors with different geometries

Organic Devices offer low-cost manufacturing and better flexibility, sustainability and solution-processability than their Si-based MOS counterparts, which make them suitable for new applications where those characteristics are an advantage. However, organic device performance is still far from that provided by CMOS technology and many issues are still unclear. In this work, a performance comparison is made between Interdigitated and Corbino geometries of Organic Thin Film Transistors (OTFT), with different areas but fabricated with identical stack materials and techniques. To this end, I-V characteristics and C-V curves of the OTFTs were measured and a Common-Source circuit was proposed and implemented for extracting relevant electrical parameters of the devices, through a standard small signal analysis. The parameter extraction methodology in the frequency domain proposed allows rapid testing of the device/circuit performance of this technology, which for the first time is applied to organic devices. Results show that despite the large voltages, organic transistors exhibit similar channel dimension dependencies to MOS devices and can be also described by the same small signal model