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'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 107108. 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.