Design Concept for High-LUMO-level Fullerene Electron-acceptors for Organic Solar Cells

Abstract

Abstract This review article describes design concept, synthesis, and features of fullerene derivatives having high lowest unoccupied molecular orbital (LUMO) levels to achieve high open-circuit voltage in organic thin-film photovoltaic devices. Installation of organic electron-donating groups onto fullerene and decrease of the size of the fullerene π-electron-conjugated system raise the LUMO levels, affording high-performance organic solar cells. Addition of the methano group as the smallest carbon addend to fullerene to obtain 56π-electron fullerene derivatives is likely a promising strategy for this purpose.