Enhancement of hole injection in pentacene organic thin-film transistorof O 2 plasma-treated Au electrodes

The effect of oxygen plasma treatment on enhancement of hole mobility was demonstrated using pentacene organic thin-film transistors (OTFTs) with bottom-contact Au electrodes. Linear field-effect mobility increased from 3.2 × 10 − 2 to 7.4 × 10 − 2 cm 2 ∕ V s as the Au electrodes were treated with O 2 plasma. Secondary electron emission spectra revealed that the work function of oxygen plasma-treated Au is 0.5 eV higher than that of untreated Au. This led to a reduced hole injection barrier at the interface of Au with pentacene, increasing the field-effect mobility of OTFTs.