Renaissance of Fused Porphyrins: Substituted Methylene-Bridged Thiophene-Fused Strategy for High-Performance Dye-Sensitized Solar Cells

Abstract

Over the last decades, porphyrin sensitizers have made a remarkable contribution to performance improvement in dye-sensitized solar cells (DSSCs). In particular, versatile push–pull-type porphyrin sensitizers have achieved power conversion efficiencies (η) over 10% as a result of their improved light-harvesting abilities. Meanwhile, aromatic ring fusion to a porphyrin core is an attractive option for highly efficient DSSCs because of its expanded π-conjugation and resultant red-shifted absorption. Nevertheless, aromatic-fused porphyrin sensitizers have suffered rather low cell performances due to their mismatch of HOMO–LUMO levels, high aggregation tendency, and short lifetime of the excited states. Bearing these in mind, we envisioned that the fusion of substituted methylene-bridged small aromatic ring to a porphyrin core would overcome these drawbacks, boosting the cell performance. Herein, we report a series of substituted methylene-bridged thiophene-fused porphyrins, AfZnP, DfZnP, and DfZnP- i Pr. After optimization, DSSC with the donor-side thiophene-fused DfZnP- i Pr achieved an η-value of 10.1%, which is comparable to that of DSSC with GY50 (10.0%), a representative high-performance push–pull-type porphyrin sensitizer. More importantly, cosensitization of DfZnP- i Pr with a complementary sensitizer LEG4 further led to an η-value of 10.7%, which is the highest value ever reported for DSSCs with fused porphyrin sensitizers. Therefore, our strategy will reboot the exploration of aromatic-fused porphyrin sensitizers for high-performance DSSCs.

A Blue Photosensitizer Realizing Efficient and Stable Green Solar Cells via Color Tuning by the Electrolyte

“…[ 9,10 ] Red semitransparent DSCs obtained by ruthenium bipyridine complexes dyes or some organic dyes are most transmissive in the long‐wavelength range. [ 11–13 ] Blue semitransparent DSCs obtained by diketopyrrolopyrrole dyes [ 14 ] or polycyclic aromatic hydrocarbon dye [ 15 ] are most transmissive in the short‐wavelength range, and green ones by squaraine dyes [ 16 ] or zinc porphyrin dyes [ 17–20 ] in the medium‐wavelength range. As the human eyes are most sensitive at 555 nm under daylight conditions, [ 21 ] the green semitransparent DSC is the most appealing for the see‐through PV products.…”

Photovoltaic Performance of Porphyrin‐Based Dye‐Sensitized Solar Cells with Binary Ionic Liquid Electrolytes

“…The current study deals with a green porphyrin sensitizer which is an entirely different class of dyes. Molecular design and spectral tuning of the porphyrin dyes were investigated and then applied in DSCs with volatile solvent‐based electrolytes . Earlier, we reported the synthesis and characterization of Y350 dye and its application in DSC with volatile solvent‐based cobalt(II)/(III) redox electrolyte.…”

Molecular Engineering of Simple Metal‐Free Organic Dyes Derived from Triphenylamine for Dye‐Sensitized Solar Cell Applications

“…However, the rarity of sources, high costs, environmental issues related to the content of heavy metals, and low molar extinction coefficients of the ruthenium complexes limited their further applications . However, advantages such as synthetic versatility, high molar extinction coefficients, low cost, and environmental friendliness of organic donor–acceptor (D–A) dyes make them particularly attractive, relative to organometallic dyes …”

“…[18,19] However,a dvantages such as synthetic versatility,h igh molar extinction coefficients, low cost, and environmental friendliness of organic donor-acceptor (D-A) dyes make them particularly attractive, relative to organometallic dyes. [20][21][22][23] The redox electrolyte is another key component for the performance of the DSCs. It affects the photovoltages of the DSCs as ar esult of the involved redox energies and kinetics related to dye regeneration.…”