Effect of active layer thickness on the electrical characteristics of polymer thin film transistors

In this paper, we analyze the variation of the threshold voltage VT and carrier mobility μfet with the active layer thickness of polymer thin film transistors (PTFTs). The value of VT was observed to become more negative as the active layer thickness decrease, while mobility slightly increased. Simulations obtained for different active layer thickness were first validated with experimental data from measured devices with known active layer thickness. Then using the calibrated simulator, it was found that as the semiconductor thickness decreased, the charge per square units in the active layer changes, establishing the cause of both of these behaviors.