High-Performance Stable n-Type Indenofluorenedione Field-Effect Transistors

Abstract

We developed high-performance stable n-type organic field-effect transistors (OFETs) using indenofluorenediones with different numbers of fluorine substituents (MonoF-IF-dione, DiF-IF-dione, and TriF-IF-dione). Top-contact OFETs were fabricated via the vacuum deposition of indenofluorenediones as the semiconducting channel material on polystyrene-treated SiO(2)/Si substrates. TriF-IF-dione FETs with Au source/drain contacts exhibited good device performances, with a field-effect mobility of 0.16 cm(2)/(V s), an on/off current ratio of 10(6), and a threshold voltage of 9.2 V. We found that the electrical stability for OFETs based on indenofluorenedione improved with the number of fluorine substituents, which was attributed to higher activation energies for charge trap creation. Moreover, the TriF-IF-dione FETs yielded excellent environmental stability properties, because the LUMO energy levels were relatively low, compared with those of the MonoF-IF-dione FETs.