Browsing by Author "Guzel, Emre"

Now showing 1 - 2 of 2

Non-Aggregating Zinc Phthalocyanine Sensitizer With Bulky Diphenylphenoxy Donor Groups and Pyrazole-3 Acid Anchoring Group for Coadsorbent-Free Dye-Sensitized Solar Cells
(Pergamon-elsevier Science Ltd, 2021) Yildiz, Burak; Arslan, Baris Seckin; Guzel, Emre; Nebioglu, Mehmet; Menges, Nurettin; Sisman, Ilkay; Sener, M. Kasim
A novel unsymmetrical zinc phthalocyanine complex (PCA-ZnPc-3) containing six 2,6-diphenylphenoxy donor groups and pyrazole-3-carboxylic acid anchoring group has been synthesized and used as a sensitizer for dye sensitized solar cells (DSSCs). The optical, electrochemical and photovoltaic characteristics were evaluated and compared with the dyes containing the same anchoring group and tert-butyl (PCA-ZnPc-1) or hexylsulfanyl (PCA-ZnPc-2) donor groups, developed by our group. The DSSC with PCA-ZnPc-3 exhibited a higher power conversion efficiency (PCE) of 2.04% as compared to that of PCA-ZnPc-1 (PCE = 1.74%) and PCA-ZnPc-2 (PCE = 1.89%). This enhancement in efficiency may be ascribed to the less dye aggregation and appropriate dye coverage. These results suggest that the incorporation of 2,6-diphenylphenoxy into pyrazole-3-carboxylic acid based zinc phthalocyanine sensitizers can improve photovoltaic performance of DSSCs.
Pyrazole-3 Acid as a New Anchoring Group for Phthalocyanine-Sensitized Solar Cells
(Pergamon-elsevier Science Ltd, 2018) Yildiz, Burak; Guzel, Emre; Menges, Nurettin; Sisman, Ilkay; Sener, M. Kasim
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.