Patterned Electrode Vertical OFET: Analytical description, switching mechanisms and optimization rules

Patterned Electrode Vertical Organic Field Effect Transistor (PE-VOFET) operational behavior is examined in this work with the use of self-consistent numerical model and experimental measurements. The device is described as a single carrier type diode where one of its electrode's electrical properties could be altered under the gate influence, switching the current regime between the Contact Limited (CL) and the Space Charge Limited (SCL) regimes. Here we show that two distinct mechanisms can play a role in the switching process; inducing the formation of virtual contacts for the ideal Schottky barrier-based device or inducing a potential barrier which eliminates charge extraction for the non-ideal ohmic contact-based device. The latter is further examined by varying the Patterned Electrode (PE) thickness which alters the sub-threshold swing performances, determining the gate bias required to turn off the device. We further provide optimization rules regarding the active layer thickness (channel length), which hold for the 'ideal' performances of the single layer PE-VOFET. Based on the aforementioned models and optimization rules, we provide guidelines for the ideal PE-VOFET structure and future challenges in its fabrication.