Synthesis of asymmetric zinc phthalocyanine with bulky diphenylthiophenol substituents and its photovoltaic performance for dye-sensitized solar cells

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2016-05, Vol.321, p.248-256
• Main Authors: Shi, Wenye, Peng, Bosi, Guo, Yingying, Lin, Li, Peng, Tianyou, Li, Renjie
• Format: Article
• Language: English
• Subjects: Asymmetric zinc phthalocyanine; Conversion efficiency; Dye-sensitized solar cell; Red/near-IR light absorption
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2016.02.009

[Display omitted] •Novel asymmetric ZnPc derivative was prepared as dye of DSSCs.•Zn-tri-PcNc-9 with six diphenylthiophenol groups has broad Q-band absorption.•CDCA as coadsorbent can retard ZnPc molecule aggregates and charge recombination.•Zn-tri-PcNc-9-sensitized cell containing CDCA yields 3.61% efficiency.•S atoms in ZnPc’s substituents expand the solar cell’s red/near-IR responsive range. Asymmetric zinc phthalocyanine derivative (Zn-tri-PcNc-9) bearing one carboxylic and six bulky diphenylthiophenol groups was synthesized as a sensitizer for dye-sensitized solar cells. The obtained Zn-tri-PcNc-9 exhibits strong and expanded Q-band absorption peak (at ∼741nm) in the red/near-IR light (600–800nm) range, and its photovoltaic performance in sensitizing TiO2-based solar cell can be significantly improved by using chenodeoxycholic acid (CDCA) as co-adsorbent due to the retarded charge recombination. Under an optimal sensitization condition, the corresponding solar cell exhibits an efficiency of 3.61%, which is improved by 144% as compared to the solar cell without CDCA. Moreover, Zn-tri-PcNc-9-sensitized solar cell shows a maximum incident photo-to-current conversion efficiency of 31.6% at ∼730nm, red-shifted by ∼20nm as compared to that (∼710nm) of its O-substituted analog (Zn-tri-PcNc-8) bearing six diphenylphenoxy groups, suggesting an effective solution to expand the red/near-IR responsive range of the ZnPc-sensitized solar cell, and also demonstrating a possibility for future panchromatic sensitizing agents in dye-sensitized solar cells.