New porphyrin dyes containing a hydrazide anchor for dye-sensitized solar cells

Abstract

Herein, we prepared two new zinc porphyrin dyes (JA4 and JA5) containing different anchoring groups and applied them in dye-sensitized solar cells. The hydrazide unit was used as an anchoring group for a DSSC, and the device based on the JA5 containing hydrazide anchor also shows a high PCE of 5.49% with a J_sc of 11.57 mA cm⁻² and a V_oc of 737 mV. COOH is the most common anchor, but it is prone to dissociate from the TiO₂ surface, especially under alkaline conditions. Interestingly, the hydrazide anchor shows better water-stability under various aqueous conditions compared with the COOH anchor, including acidic, neutral and alkaline conditions. In addition, a hydrazide unit is very easy to synthesise, thus, hydrazide can be a promising anchoring group for DSSCs.