Abstract
We synthesized a linear π-conjugated small molecule (β-DH5T) based on thiophene, using the palladium-catalyzed Suzuki coupling. The oligothiophene was designed to contain β-substituted solubilizing alkyl groups to facilitate solution processing. The organic photovoltaic cell based on β-DH5T:PC71BM gave a power conversion efficiency of 0.46% with a short-circuit current of 4.69 mA/cm2, an open-circuit voltage of 0.60 V, and a fill factor of 0.35, giving under AM 1.5G illumination (100 mW/cm2). The optical and electrochemical properties and molecular alignment of oligothiophene were investigated using UV-visible absorption spectroscopy, cyclic voltammetry, and thin-film X-ray diffraction studies.
Funding
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2012R1A1A3005083).