Pyrazole-3-carboxylic acid as a new anchoring group for phthalocyanine-sensitized solar cells

• Published in: Solar energy 2018-11, Vol.174, p.527-536
• Main Authors: Yıldız, Burak, Güzel, Emre, Menges, Nurettin, Şişman, İlkay, Kasım Şener, M.
• Format: Article
• Language: English
• Subjects: Anchoring; Anchoring group; Bearing; Carboxylic acids; Conversion; Dye-sensitized solar cells; Dyes; Efficiency; Electrons; Energy conversion efficiency; Photovoltaic cells; Phthalocyanine; Pyrazole; Pyrazole-3-carboxylic acid; Solar cells; Solar energy; Solar power; Titanium dioxide; Zinc
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2018.09.039

[Display omitted] •Unsymmetrical ZnPc bearing a new pyrazole-3-carboxylic acid anchoring group synthesized as dye of DSSCs.•Pyrazole-3-carboxylic acid can anchor to the TiO2 through the N and O atoms.•Electron-withdrawing nitrogen atom of anchor improved electron injection efficiency.•The photovoltaic performance of new dye is higher than that of the similar phthalocyanines containing only carboxylic acid. We have designed and synthesized an unsymmetrical zinc phthalocyanine (PCA-ZnPc-1) bearing an electron-withdrawing pyrazole-3-carboxylic acid anchoring group and three electron-donating tert-butyl groups as a sensitizer for dye-sensitized solar cells (DSSCs). PCA-ZnPc-1 sensitized solar cell showed a modest power conversion efficiency (1.74%), which may suffer from the flexible and non-conjugated oxygen linker on the sensitizer. However, the obtained efficiency is found to be three to four times higher than that of the unsymmetrical ones bearing only carboxylic acid due to the combination of pyrazole and carboxylic acid moieties within the same anchoring group, which enhances the binding of the dye on the TiO2 surface and results in an increase of electron injection efficiency. Therefore, the pyrazole-3-carboxylic acid is a promising anchoring group for developing new phthalocyanines to build efficient DSSCs.