Simulation study of the electrical behavior of bottom contact organic thin film transistors

Organic thin-film transistors (OTFTs) are making significant inroads into various large-area applications. Organic materials provide a low-cost alternative to silicon in the electronics industry as they can be fabricated at low temperatures and with high throughput on a wide range of unconventional substrates, such as glass, plastic, fabric and paper. This paper presents a simple 2D simulation study of the electrical characteristics of bottom-contact OTFTs. The pentacene has been used as the organic semiconductor in the active film. It has been demonstrated that the trap-density of states plays an important role in the device conduction mechanism and hence degrades the performance. The simulated results show similar trends with the experimental results which verify the accuracy of the models used for simulation of OTFTs. It is demonstrated that the field-dependent mobility behavior of OTFTs is correctly modeled by the Poole-Frenkel mobility model. Also, the band theory used for conventional MOS devices satisfies the charge transport mechanism in OTFTs.