Organic heterostructure field-effect transistors using C60 and amorphous spirolinked compound

The authors fabricated organic heterostructure field-effect transistors using C60 and amorphous compound 2,2′,7,7′-tetra-(m-tolyl-phenylamino)-9,9′-spirobifluorene. The corresponding transistor characteristics show ambipolar charge transport behaviors. The measured hole and electron mobilities of 5.53×10−4 and 2.23×10−3cm2∕Vs were obtained. Large hysteresis in the transfer curve was observed after the transfer characteristics were measured from the on state to the off-off state and vice versa. In this case, the switch-on voltage shifted by ∼40V.