N-phenyl[60]fulleropyrrolidines: alternative acceptor materials to PC sub(61)BM for high performance organic photovoltaic cells

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 2; no. 48; pp. 20889 - 20895
• Main Authors: Karakawa, Makoto, Nagai, Takabumi, Adachi, Kenji, Ie, Yutaka, Aso, Yoshio
• Format: Journal Article
• Language: English
• Published: 01.11.2014
• Subjects: Acceptor materials; Derivatives; Devices; Donors (electronic); Energy conversion efficiency; Esters; Photovoltaic cells; Solar cells
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c4ta04857a

A series of novel soluble [60]fulleropyrrolidine derivatives bearing relatively simple substituents like [6,6]-phenyl-C sub(61)-butyric acid methyl ester (PC sub(61)BM) is synthesized under Prato reaction conditions. The photoabsorption and electrochemical properties of the fulleropyrrolidines are investigated to elucidate their molecular-level electronic properties similar to those of PC sub(61)BM. The investigations of the fulleropyrrolidines as electron acceptors based on bulk-heterojunction type organic photovoltaic (OPV) devices fabricated using P3HT as a donor show clear differences in performance depending on the substituents, and the devices based on the N-phenyl[60]fulleropyrrolidine derivatives exhibit good power conversion efficiencies (PCEs) comparable to, or even higher than, that of the standard PC sub(61)BM-based device. Finally, the OPV devices based on a low-bandgap donor polymer (PTB7) with the N-phenyl[60]fulleropyrrolidines show high PCEs up to 7.3%, which is the highest class performance among [60]fullerene-based OPV devices, indicating that N-phenyl[60]fulleropyrrolidine derivatives are a promising alternative to PC sub(61)BM for OPV acceptor materials.