Trannulenes: a new class of photoactive materials for organic photovoltaic devices

We report the first large-scale preparation of fluorinated trannulene C60F15[C(COOMe)3]3 (TMCMT) and its application as a photoactive material in organic solar cells. Two types of photovoltaic devices were fabricated: bulk heterojunction cells comprising blends of TMCMT with a polyfluorene polymer and bilayer cells based on a planar heterojunction of TMCMT with a perylene diimide. Photoluminescence quenching studies suggested that a photoinduced electron transfer occurs from polyfluorene and perylenediimide to TMCMT, therefore it behaves as photoinduced electron acceptor. Both types of solar cells comprising TMCMT as photoactive material showed clear photovoltaic effects. This proves for the first time the feasibility of the previously anticipated idea of using trannulenes as light-harvesting materials in photovoltaic devices.