Penta(organo)[60]fullerenes as acceptors for organic photovoltaic cells†
Abstract
Pentaaryl[60]fullerene derivatives, C60(C6H4Ph)5Me, C60(C6H4OPh)5Me, C60(C6H4nBu)5Me, Fe[C60(C6H4nBu)5]Cp, and Ru[C60(C6H4nBu)5]Cp have been used as acceptor materials in bulk heterojunction-type organic photovoltaic cells in combination with poly(3-hexylthiophene) as a donor material. High open-circuit voltages (up to 0.76 V) were obtained, which are attributed to the high LUMO of the penta(organo)[60]fullerenes. Scanning electron microscopic analyses of the cross-section of the devices indicated a homogeneous distribution of the donor and the acceptor compounds, which accounts for the moderate short-circuit current and photocurrent conversion efficiency (η = 1.08).