Synthesis and Characterization of Isatin-modified Quinoidal Molecules for Organic Field-Effect Transistors

Abstract

Quinoid molecules show their potential as an active layer of organic field-effect transistors (OFETs) owing to highly planar structure arisen from double bond linkages. Besides, quinoidal structure could form diradical due to tendency to recover aromaticity. Recently, isatin was used as termini for quinoidal molecules with advantages such as facile synthesis and possibility of diverse modification. Here, we designed and synthesized benzothiophene-ended quinoidal thiophene (BzTQuT) introducing fused ring at termini to extend π-conjugation and enhance intermolecular interaction for better charge transport. Material properties including diradical character were investigated to determine the effect of extended fused ring. Electrical properties were characterized by OFETs. OFETs based on BzTQuT showed maximum mobility of 0.038 cm2 V-1 s-1. Moreover, PVN was blended with BzTQuT and applied to OFETs to enhance device performance. Best mobility of 0.073 cm2 V-1 s-1 was obtained in BzTQuT:PVN blend film.