Abstract
Two novel π-conjugated small molecules based on the electron-deficient diketopyrrolopyrrole (DPP) and the electron-rich fused tetrathienoacene (TTA) frameworks are synthesized and characterized. As verified in the bandgap compression of these chromophores by electrochemistry and density functional theory (DFT) computation, these DPP-TAA derivatives exhibit substantial conjugation and ideal MO energetics for light absorption. The large fused TTA core and strong intermolecular SS interactions enforce excellent molecular planarity, favoring a close-packed thin film morphologies for efficient charge transport, as indicated by grazing incidence wide angle X-ray scattering (GIWAXS), atomic force microscopy (AFM), and transmission electron microscopy (TEM) analysis. Top-gate/bottom-contact thin film transistors based on these systems exhibit hole mobilities approaching 0.1 cm2 V-1 s-1. Organic photovoltaic cells based on DDPP-TTAR:PC71BM blends achieve power conversion efficiencies (PCE) > 4% by systematic morphology tuning and judicious solvent additive selection.
Original language | English (US) |
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Pages (from-to) | 8932-8941 |
Number of pages | 10 |
Journal | Journal of Materials Chemistry C |
Volume | 3 |
Issue number | 34 |
DOIs | |
State | Published - Jul 31 2015 |
ASJC Scopus subject areas
- General Chemistry
- Materials Chemistry