Quantitative physical analysis of gate-insulator/organic-semiconductor interaction and its impact on the OTFT performance

Organic transistor parameters (i.e. threshold, stability, on/off current ratio, subthreshold slope) are not only defined by the organic semiconductor (OSC) itself, but they strongly depend on the interface between the OSC and the gate insulator (GI), the interface between the metal electrodes (source and drain) and the OSC, as well as on the transistor structure (i.e. coplanar or staggered). Since in Organic Thin-Film Transistors (OTFTs) the charge transport takes place very close to the GI/OSC interface [1], the interaction between the insulator and the semiconductor plays an important role in determining the transistor performance [2-4]. In this work, we provide a quantitative analysis of the interaction between the gate insulator and the organic semiconductor. OTFTs made with different structures, gate insulators, organic semiconductors, and fabrication processes are considered.