Improvement of OTFT Characteristics Using Interface Control of the Organic/Inorganic Heterojunctions

Organic semiconductors have attracted much attention in recent years because of their advantages such as light weight, low cost, flexibility, and solubility. On the other hand, organic semiconductors have the disadvantages of low carrier mobility and instability in the atmosphere compared to inorganic semiconductors such as silicon. For this reason, devices using organic semiconductors, including OTFTs, have larger drive voltages and lower operation speeds than inorganic semiconductor devices. To address these issues, we propose to improve the junction surface between the inorganic insulating film and the organic semiconductor layer, which tends to occur in OTFTs, by performing plasma nitriding on the surface of the inorganic insulating film. Specifically, we estimated the high-frequency tracking characteristics of carriers in organic films from the accumulated capacitance values of C-V measurements and investigated how plasma nitriding affects the injection efficiency of carriers. As a result, we found that controlling the organic / inorganic interface by plasma nitriding improves the carrier conduction characteristics and contributes to improving the electrical properties of OTFTs.