Triphenylamine-based organic dyes containing a 1,2,3-triazole bridge for dye-sensitized solar cells via a ‘Click’ reaction

Three new organic dyes with one, two and three branched D–π–A structures derived from an electron donating triphenylamine core and connected by 1,2,3-triazole group to an electron deficient cyanoacrylate system have been conveniently synthesized via a ‘Click’ reaction. It was found that all three dyes show UV–vis absorptions in the 300–500 nm range with high molar extinction coefficients. A red-shift of UV–vis absorption band was observed in the solid thin film compared with the dioxane solution. Dye-sensitized solar cell devices based on the dyes were fabricated and tested. The one branched triphenylamine-based dye exhibits the highest energy conversion efficiency. Increase of the branched D–π–A structure around the triphenylamine core results in the decrease of energy conversion efficiency of the dyes, which can be attributed to less attachment of the dyes onto TiO2 photoanode with the enlarged molecular size of the corresponding multibranched structure.

Graphical abstractNew organic dyes based on triphenylamine core have been synthesized via a ‘Click’ reaction. The introduction of 1,2,3-triazole bridge enhances the Voc and fill factor of the DSSCs, and the increment of branched D–π–A structure results in the decrease of energy conversion efficiency.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Three new triphenylamine-based organic dyes were conveniently synthesized via a “Click” reaction. ► The bridging 1,2,3-triazole group has been introduced into dyes for DSSCs for the first time. ► The photovoltaic performance was discussed using results from the experimental study and DFT calculations.