Towards transparent electronics: fabrication of an organic transistor with a wide bandgap polymer

Abstract

We have fabricated organic thin film transistors (OTFTs) with a solution process by utilizing a novel wide bandgap conjugated polymer poly(N-(4-(9,9-dioctyl-fluoren-2-yl)phenyl)-N,N′,N′-triphenyl-l,4-phenylenediamine) (P1) as the active channel material. The transistor was constituted with a bottom-gate configuration, in which P1 was deposited on the substrate, SiO2 insulator served as the gate dielectric material and Ti/Au were used as the electrodes. The hole-transporting properties of the transistor were examined by analyzing the current–voltage (I–V) characteristics. The carrier mobility was 0.95 × 10−2 cm2 V−1 s−1 and the on/off current ratio was about 5.8 × 104. Moreover, the thin film of the novel polymer P1 exhibits very high transparency for visible light since the bandgap of P1 is 2.84 eV. The excellent electrical properties of the P1 based transistor and the nature of the high transparency of such a polymer suggest that the novel polymer P1 can potentially serve as a superior material for transparent organic electronics.