Contact resistance in organic transistors: Extraction using variable length method

The paper illustrates the contact resistance limited behavior of pentacene based organic transistor using simulation and mathematical model. The characteristic behavior of transistor is found somewhat deviated from the predicted Shockley model invariably used to predict the performance of conventional transistors. This difference is due to the existence of non-linear behavior of contacts in organic material based transistors which is a fabrication and materialistic issue. Therefore, the model is modified based on contact resistance. The existence of contact resistance for BGTC-OTFT is well validated using MATLAB model equations. Additionally the model is modified in terms of γ (mobility enhancement factor). Furthermore, the effect of variation of γ and R_C is analyzed to demonstrate the behavior of organic transistor with different parameters. Extraction of contact resistance is done through variable channel length method that closely matches to the experimental reported result.