Pushing fullerene absorption into the near-IR region by conjugately fusing oligothiophenes

Fusing two in one: The π-electron systems of fullerene and an oligothiophene were conjugately fused by an open-cage process. This led to novel fullerene-oligothiophene chromophores with significantly enhanced light-absorbing capability, which covers a wide spectral range. The fullerene band gap could be tuned to about 1 eV by a chemical approach.