Background: Dye-sensitized solar cells have received attention recently for efficient converting
sunlight to electricity. Organic dyes provide a feasible alternative due to the practical advantages, such as facile
structure tuning, easy synthesis process, and low cost. Organic sensitizers are generally designed to link the
electron donor and the electron acceptor. When light irradiated on the dyes, these dipolar molecules induce
intramolecular charge transfer from the donor to the acceptor, and the electron is then injected into TiO2 via the
anchoring groups (carboxylic acids).
Objective and Method: This work systematically synthesized the dyes containing triphenylamine as the electron
donor, a series of donor-π-acceptor as the conjugation segment, and 2-cyanoacetic acid as the electron
acceptor, where donor-π-acceptor structures are expected to enable efficiently photoinduced charge separation.
The photovoltaic performance of the dyes is significantly related to the linker type.
Results: The charge transfer from the excited dye molecules to the conduction band of TiO2 is improved in the
styrene-π -linked dye, showing highly effective improvement in the efficiency of the corresponding devices as
compared dye-based devices with N-methylpyrrole, 3,4-ethylenedioxythiophene linkers and no linker. The
device with N-methylpyrrole-linker-based dye bearing positions of C3 and C4 on N-methylpyrrole linker has
the lowest conjugation effect and efficiency. Styrene-linker-based dye shows a broad incident-photon-tocurrent
conversion efficiency response with a signal of up to 670 nm, covering most of the ultrviolet-visible
Conclusion: Device efficiencies of 5.18% and 7.56% for dye-sensitized devices using Styrene-linker-based
dye and N3 dye, respectively, assembled using the same method and measured under AM 1.5 irradiation.