Tetracene-based field-effect transistors using solution processes

Abstract

Tetracene of high purity was produced in a quantitative yield from a new precursor, which consists of a carbonyl bridge across the benzene ring. The precursor can be synthesized readily through four steps in an overall yield of 30%. Its structure, along with three other synthetic intermediates, was resolved by X-ray crystal diffraction analyses. High performance organic thin film transistors (OTFTs) were fabricated by using tetracene generated directly from this precursor without further purification being necessary. Two kinds of OFET devices were investigated, i.e., single crystal type and thin film type, while both were processed through solutions. The device made with a single crystal of tetracene displayed a charge carrier mobility of 0.56 cm² V⁻¹ s⁻¹ with an on/off ratio of 1.0 × 10⁵. Devices made with thin films showed a charge mobility of 6.42 × 10⁻² cm² V⁻¹ s⁻¹ with an on/off ratio of 2.6 × 10⁴. These performances are comparable with those fabricated by using a vapor deposition method.