Controlling field-effect mobility in pentacene-based transistors by supersonic molecular-beam deposition

We show that pentacene field-effect transistors, fabricated by supersonic molecular beams, have a performance strongly depending on the precursor's kinetic energy (K-E). The major role played by K-E is in achieving highly ordered and flat films. In the range K-E approximate to 3.5-6.5 eV, the organic field effect transistor linear mobility increases of a factor similar to 5. The highest value (1.0 cm(2) V-1 s(-1)) corresponds to very uniform and flat films (layer-by-layer type growth). The temperature dependence of mobility for films grown at K-E > 6 eV recalls that of single crystals (bandlike) and shows an opposite trend for films grown at K-E <= 5.5 eV. (c) 2006 American Institute of Physics.