Organic materials based on hetero polycyclic aromatic hydrocarbons for organic thin-film transistor applications

Abstract

The synthesis and characterization of new hetero polycyclic aromatic hydrocarbons (HPAHs) are reported as potential lead molecules in organic semiconductor devices with tetraimidazolo or tetrapyrazolo benzo-fused coronene as the main framework. The incorporation of hetero atoms into polycyclic aromatic hydrocarbons (PAHs) by the Corey-Fuchs reaction followed by photochemical cyclization using iodine has been described for its carrier mobility and hole transport properties. The synthesized coronenes, Tetraimidazocoronene (TIC), Tetraimidazobenzocoronene (TIBC), Tetraimidazodibenzocoronene (TIDBC), Tetrapyrazolocoronene (TPC), Tetrapyrazolobenzocoronene (TPBC), and Tetrapyrazolodibenzocoronene (TPDBC), have good physicochemical properties and are supported with DFT/TDDFT studies. On an ODTS-SiO2 substrate at room temperature, the reported compounds were utilized to fabricate organic thin-film transistors (OTFTs) and shown hole mobilities from 0.16 to 0.71 cm2/Vs with an on/off ratio of 102 to 106. Thin-film transistor based on compound 5b as the channel material displays an electron mobility of 1.94 cm2/Vs with an on/off ratio of 102.