Top-gate staggered poly(3,3′′′-dialkyl-quarterthiophene) organic thin-film transistors with reverse-offset-printed silver source/drain electrodes

Here, we report on high-performance top-gated poly(3,3'''-dialkyl-quarterthiophene) (PQT-12) organic thin-film transistors (OTFTs) with reverse-offset-printed (ROP) silver (Ag) source/drain (S/D) electrodes. OTFT devices with ROP S/D electrodes using Ag nanopaste show higher performance (similar to 0.01 cm(2)/Vs) than those fabricated by vacuum electron beam evaporation with conventional photolithography and a standard lift-off process (similar to 1 x 10(-3) cm(2)/Vs). This dissimilarity is attributed to the higher work function (-4.9 eV) of the ROP Ag electrode due to AgO formation on the Ag surface during thermal annealing. This results in a low interfacial hole injection energy barrier between the S/D electrodes and the PQT-12 semiconductor. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4755878]