Improving Performance of Pentacene Field-effect Transistors by Optimizing Substrate Temperature and Active Layer Thickness

High performance pentacene-based organic field-effect transistors (OFETs) with different substrates temperatures and film thicknesses were fabricated. The device performance improved visibly the substrate temperature was 69 degrees C and the pentacene film thickness was about 39nm. The field-effect mobility reached as high as 0.42cm(2)/Vs, the subthreshold swing was 534mV/dec, and the on/off ratio was 10(7)-10(8). Electrical properties and film morphology of the device indicate that the substrate temperature affects grain size of the film, and the film thickness affects the trap density of the film.