[70]Fullerene-Based Materials for Organic Solar Cells

• Published in: ChemSusChem 2011-01, Vol.4 (1), p.119-124
• Main Authors: Troshin, Pavel A., Hoppe, Harald, Peregudov, Alexander S., Egginger, Martin, Shokhovets, Sviatoslav, Gobsch, Gerhard, Sariciftci, N. Serdar, Razumov, Vladimir F.
• Format: Article
• Language: English
• Subjects: Absorption; Chlorobenzenes - chemistry; Electric Power Supplies; Esters; Fullerenes - chemistry; Optical Phenomena; Organic Chemicals - chemistry; Propionates - chemistry; Solar Energy; Solubility; Thiophenes - chemistry
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201000246

The synthesis, characterization and photovoltaic study of two novel derivatives of [70]fullerene, phenyl‐C71‐propionic acid propyl ester ([70]PCPP) and phenyl‐C71‐propionic acid butyl ester ([70]PCPB), are reported. [70]PCPP and [70]PCPB outperform the conventional material (6,6)‐phenyl‐C71‐butyric acid methyl ester ([70]PCBM) in solar cells based on poly(2‐methoxy‐5‐{3′,7′‐dimethyloctyloxy}‐p‐phenylene vinylene) (MDMO‐PPV) as a donor polymer using chlorobenzene (CB) or dichlorobenzene (DCB) as solvents. AFM data suggest that improvement of the device efficiency should be attributed to the increased phase compatibility between the novel C70 derivatives and the polymer matrix. [70]PCPP and [70]PCBM showed more or less equally high performances in solar cells comprising poly(3‐hexylthiophene) (P3HT) as a donor polymer. Optical modeling revealed that the application of [70]fullerene derivatives as acceptor materials in P3HT‐based bulk heterojunction solar cells might give approximately 10 % higher short circuit current densities than using C60‐based materials such as [60]PCBM. The high solubility of [70]PCPP and [70]PCPB and their good compatibility with the donor polymers suggest these fullerene derivatives as promising electron acceptor materials for use in efficient bulk heterojunction organic solar cells. She sells C cells: Novel highly soluble derivatives of [70]fullerene show promising efficiencies in organic bulk heterojunction solar cells comprising the polymers MDMO‐PPV and P3HT as electron donors. A clear correlation is revealed between the degree of phase separation in the fullerene/polymer blends (average cluster size) and their photovoltaic performance.