Increasing the power output of a CdTe solar cell via luminescent down shifting molecules with intramolecular charge transfer and aggregation-induced emission characteristics

A series of tetraphenylethylene (TPE) based luminescent downing-shifting (LDS) molecules was synthesized based on a new design strategy for electron donor–acceptor conjugated fluorophores, in which TPE was paired with malononitrile and used as an electron donor. Because of their strong characteristics of intramolecular charge transfer (ICT) and aggregation-induced emission (AIE), the synthesized fluorophores exhibit both large Stokes shifts (129–146 nm) and high quantum yields (0.84–0.99). Applied PMMA solid films doped with the synthesized molecules on the surface of a CdTe solar cell can significantly increase its short circuit current density (Jsc) by a magnitude of 6–10%.