Novel D-A type dyes based on BODIPY for solution processed organic polymer solar cells

Boron dipyrromethene (BODIPY) derivatives have good optoelectronic properties and thermal stability. However, it is rarely for such materials to use in bulk heterojunction (BHJ) organic solar cell. In this study, a variety of donor-acceptor (D-A) type boron dipyrromethene (BODIPY) based dyes were designed and synthesized for polymer solar cells (PSCs), namely BDH1-4. Thermal stability, photochemical properties, charge transport and BHJ morphology were investigated to elucidate factors affecting the photovoltaic performance in this class of polymers. These BDHs exhibit fine solubility in conventional solvents, good thermal stability, excellent panchromatic absorption in solution and in film. Furthermore, the absorption wavelength of BDH1-4 covers full color absorption in the range of 300-800 nm and has a relatively low HOMO level from -5.01 to -5.66 eV. Among them, BDH4/PC71BM based PSCs exhibit highest power conversion efficiency (PCE) of 3.69% with a Jsc of 9.92 mA cm(-2), a Voc of 0.63 V and a FF of 59.1%.