Charge Transport in Organic Transistors Accounting for a Wide Distribution of Carrier Energies—Part II: TFT Modeling

A physically based analytical model of the drain current of an organic thin-film transistor is proposed. It is compared with the measurements collected from transistors made with different gate insulators, organic semiconductors, and fabrication processes. The extracted model parameters provide quantitative information on the charge transport in the active layer of the transistor. The analysis suggests that the tail states are an intrinsic property of the organic semiconductor, whereas the deep states arise from the interaction between the semiconductor and the gate insulator. The relative importance of tail and deep localized states is related to the operating regions of the transistor. The resulting mathematical expressions are simple and suitable for computer-aided design implementation.