N-Type Conjugated Materials Based on 2-Vinyl-4,5-dicyanoimidazoles and Their Use in Solar Cells

The high-yield syntheses of a new class of n-type conjugated materials based on the Heck coupling of 2-vinyl-4,5-dicyanoimidazole with selected dibromoaromatics is reported. The resultant materials have tunable HOMO−LUMO levels and photoluminescence ranging from deep blue to red. Solution-processed organic solar cells with external quantum efficiencies exceeding 14% could be prepared by blending selected novel materials with poly-(3-hexylthiophene) (P3HT).