Improving Mobility and Stability of Organic Field-Effect Transistors by Employing a Tetratetracontane Modifying PMMA Dielectric

Devise stability is another important problem for hindering the commercial applications of organic field-effect transistors (OFETs) besides the mobility. In this paper, an abnormal instability was observed in the OFET with a pure polymer poly(methyl methacrylate) (PMMA) dielectric due to the minority carriers trapped at the pentacene/PMMA interface. By inserting a tetratetracontane modification layer between PMMA and pentacene, not only the morphology of the deposited pentacene was greatly improved, but also the trap density at the pentacene/dielectric interface was reduced, demonstrated by the investigation of the atomic force microscopy, and the analysis of the subthreshold swing and flicker noise, respectively. As a result, both the stability as well as the mobility of the OFET was obviously improved.