New series of BODIPY dyes: Synthesis, characterization and applications in photovoltaic cells and light-emitting diodes

Abstract We report on the straightforward synthesis, characterization and photovoltaic and light-emission applications of two series of BODIPY molecules with aryloxy or alkoxy groups bonded to the boron centre. The crystal structures of two of these new dyes are also presented. The BODIPYs have absorption features similar to those of the analogous boron-fluorinated BODIPYs used as starting materials. However, the fluorescence properties vary significantly with the nature of the aryloxy/alkoxy group. The photovoltaic performance in bulk heterojunction solar cells of the newly synthesized compounds does not, however, outperform that of the parent boron-fluorinated BODIPYs. The maximum power conversion efficiency was obtained with two non-fluorescent BODIPYs, reaching 0.9%, compared with 2.79% obtained for the cells based on the corresponding boron-fluorinated precursor. The fluorine replacement by aryloxy/alkoxy groups had instead a positive effect on the light-emitting properties of the compounds of one of the series, leading to higher maximum luminance (114 cd/m2) and efficiency (0.057 cd/A), compared to devices based on the corresponding boron-fluorinated dye (35 cd/m2 and 0.015 cd/A, respectively).