Ultrafast multi-phasic electron injection in efficient non-aggregated hyperbranched zinc phthalocyanine sensitized solar cells

摘要

A novel hyperbranched zinc phthalocyanine dye, i.e. HBZnPc-COOH, was synthesized, characterized, and applied intodye-sensitized solar cells (DSSCs) as TiOsub2/sub sensitizer. UV-visible absorption, steady-state fluorescence, femtosecondtime-resolved fluorescence, cyclic voltammetry, current–voltage characteristics, and photoelectrical properties of theactive material/device were investigated. The utilization of hyperbranched structure was proved to be able to solve theaggregation issue of phthalocyanine dyes on TiOsub2/sub surface which has been widely considered as one of the key limitingissues that severely lower the efficiencies of phthalocyanine dye sensitized solar cells. With appropriate highest occupiedmolecular orbital and lowest unoccupied molecular orbital energy levels, HBZnPc-COOH exhibited efficient andultrafast multi-phasic electron injection from both the Soret band and Q band to the conduction band of TiOsub2/sub, leading toa solar cell power conversion efficiency of 1.15% and a high incident photon to current conversion efficiency of 66.7%at 670 nm.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.