Synthesis and optoelectronic properties of new acceptor-donor-acceptor type solution processed conjugated small molecules for optoelectronics

ABSTRACT

We designed and synthesized two new acceptor-donor-acceptor (A-D-A) small molecules SM-1 and SM-2 by connecting benzodithiophene (BDT) and dithienopyrrole (DTP) are electron rich donor units, dialkoxyphenylenedithiophene as π-spacer and 2,4 thiazolidinedione as terminal acceptor unit respectively. The SM-1 and SM-2 showed broad absorption windows with optical band gaps of 1.7 and 1.8 eV respectively, and also possess high thermal stabilities and suitable energy levels for optoelectronic applications. Especially, SM-2 shows a maximum power conversion efficiency of 1.26%, and hole mobility of 4.6 × 10⁻³ cm²/V.s in conventional organic solar cells and organic field effect transistor devices respectively.

KEYWORDS:

• Benzodithiophene
• dithienopyrrole
• organic solar cell
• organic field effect transistor

Acknowledgments

This work was supported by a grant from the National Research Foundation of Korea (NRF) of the Ministry of Science, ICT & Future Planning (MSIP) of Korea (NRF-2011-0028320) and the Pioneer Research Center Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT & Future Planning (MSIP) of Korea (NRF-2013M3C1A3065522).