Bipolar Charge Transport Properties in Air-Stable Organic Heterostructure Field-Effect Transistors

摘要

Air stable and ambipolar charge carrier transport is realized in organic field-effect transistors using a heterostructure of thin films of Pentacene and NTCDI-C8F15. The analysis of the extracted charge mobilities of transistors reveals that under an appropriate set of bias conditions the channel current in device created a new conductive path way at the interface of heterojunction. Measurement of the output and transfer characteristics gave the hole mobility of μ_h = 1.2 cm~2/Vs and the electron mobility of μ_e = 2.0x10~(-3) cm~2/Vs. These values are still comparable with the highest values reported previously. In addition, the improvement of hole mobility is attributed to the elimination of trapped holes and modification the surface morphology of pentacene due to introduction of the NTCDI-C8F15 thin film as buffer layer for the SiO2/Si contact. Finally, this ambipolar device is available for practical complementary inverters to form the CMOS integrated circuits.