5′,5″-(9,10-Bis((4-hexylphenyl)ethynyl) anthracene-2,6-diyl)bis(5-hexyl-2,2′-bithiophene) as an Organic Semiconductor and its Application to Thin Film Transistors

Abstract

New anthracene-containing conjugated molecules have been synthesized through Stille coupling reaction. 2,6-Dibromo-9,10-bis(4-hexylphenyl)ethynyl)anthracene and 2,6-dibromo-9,10-bis(phenylethynyl)anthracene were reacted with tributyl(5′-hexyl-2,2′-bithiophen-5-yl)stannane to yield 5′,5″-(9,10-bis(phenylethynyl)anthracene-2,6-diyl)bis(5-hexyl-2,2′-bithiophene), 1 and 5′,5″-(9,10-bis((4-hexylphenyl)ethynyl) anthracene-2,6-diyl)bis(5-hexyl-2,2′-bithiophene), 2. The molecule, 2 only exhibit good solubility in common organic solvents and good self-film-forming properties. The semiconducting properties of the molecule, 2 were evaluated in organic thin film transistors (OTFTs). The molecule, 2 exhibits charge carrier mobilities—as high as 5.3 × 10⁻³ cm² V⁻¹ s⁻¹(I_ON/I_OFF = 2.43 × 10⁵) without thermal annealing process.

Keywords:

• Anthracene
• bithiophene
• conjugated molecules
• mobility
• organic thin film transistor
• semiconductor

Acknowledgment

This study was supported by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy, Republic of Korea (M2007010004) and by the Korea Science and Engineering Foundation grant (2009-0054103). This work was also supported by Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF20100020209). Particularly, Prof. D.H. Choi thanks the financial support by the Seoul R&BD Program (10543, 2009–2010).

Notes

^a Before annealing.

^b HOMO(eV) – .