New Fluorinated Dithienyldiketopyrrolopyrrole Monomers and Polymers for Organic Electronics

Diketopyrrolopyrrole (DPP) derivatives are among the most efficient materials studied for both polymer solar cells (PSCs) and organic field-effect transistors (OFETs) applications. We report here the synthesis of new fluorinated dithienyldiketopyrrolopyrrole (fDT-DPP) monomers suitable for direct heteroarylation polymerization. fDT-DPP copolymers were then prepared to probe the effect of the fluorination. It was found that they feature deeper HOMO energy levels and smaller bandgaps than their non-fluorinated analogues. Moreover, some fDT-DPP copolymers show ambipolar behavior when tested in OFETs. For example, P2 shows hole mobility up to 0.8 cm2 V–1 s–1 and electron mobility up to 0.5 cm2 V–1 s–1. Inverted PSCs with power conversion efficiency (PCE) up to 7.5% were also obtained for P5. These results reported here (OFETs and PSCs) confirm that the fluorination of dithienyl-DPP moieties improves the performance of organic electronics devices. This study is also evidencing the strength of the direct hetero...