In Situ Probing Thickness Dependence of the Field Effect Mobility of Naphthalenetetracarboxylic Diimide-Based Field-Effect Transistors

摘要

We present an in situ vacuum measurement in the study of electrical characteristics of n-channel OFETs based on NTCDI-C8F15 semiconductors. Electron mobility of NTCDI-C8F15 OFETs was estimated as a function of the number of ML using in situ electrical measurement. The electron mobility has been observed for the thin film transistor of NTCDI-C8F15 as thin as 2 ML (~ 5.4 nm). Field-effect mobilities rapidly increase with the increase of the film thickness. Electron mobility of OFETs reaches saturation thickness (do) about 3.5 ML. Our experimental results indicated that the molecular layers beyond do contribute little to the carrier transport in the semiconducting channel. Our experimental results have demonstrated that the grown fashion of the first few ML of NTCDI-C8F 15 on the substrate strongly influences the carrier mobility, threshold voltage, and on-off ratio.