Output Properties of C₆₀ Field-Effect Transistors with Au Electrodes Modified by 1-Alkanethiols

Abstract

Field-effect transistors (FETs) with thin films of C60 have been fabricated with Au electrodes modified by a series of 1-alkanethiols. All C60 FETs show n-channels of normal FET properties. It has been found that the output properties for the FETs with the Au electrodes modified by 1-alkanethiols with long alkyl chains are largely affected by the carrier−injection barrier (i.e., the current vs drain/source voltage plots exhibited concave-up nonlinearity at low voltage regions). The output properties are substantially dominated by an additional tunneling barrier of 1-alkanethiols inserted into the junction of the Au electrode and C60 thin films, and the parameters associated with the junction barrier height and tunneling efficiency were determined from the output properties based on the thermionic emission model for double Schottky barriers.