High mobility organic semiconductor formulations with excellent uniformity across large area substrates are prepared via the use of formulations containing small molecule and high permittivity semiconducting oligomers. The use of these high-k (k > 3.3) oligomers allows control of the wetting via the manipulation of the surface energy of the substrate being coated. Organic thin film transistors results with mobilities of up to 5 cm2 V-1 s-1, standard deviation <10 %, on/off ratios of 109 are presented.