Transport properties of field-effect transistor with Langmuir-Blodgett films of C60 dendrimer and estimation of impurity levels

Field-effect transistor (FET) device has been fabricated with Langmuir-Blodgett films of C-60 dendrimer. The device showed n-channel normally off characteristics with the field-effect mobility of 2.7x10(-3) cm(2) V-1 s(-1) at 300 K, whose value is twice as high as that (1.4x10(-3) cm(2) V-1 s(-1)) for the FET with spin-coated films of C-60 dendrimer. This originates from the formation of ordered pi-conduction network of C-60 moieties. From the temperature dependence of field-effect mobility, a structural phase transition has been observed at around 300 K. Furthermore, the density of states for impurity levels was estimated in the Langmuir-Blodgett films. (c) 2007 American Institute of Physics.