Organic dyes containing a hydrazone moiety as auxiliary donor for solid-state DSSC applications

• D-D-π-A architecture metal-free organic dyes for solid-state DSSCs have been synthesized.
• The sensitizer series was designed to develop a structure-property relationship.
• Dyes are obtained using cheap starting materials and simple synthetic procedures.
• Solid-state dye-sensitized solar cells have been constructed.
• The best overall conversion efficiency of solid-state device was 3.9%.

D-D-π-A architecture metal-free organic dyes, containing a hydrazone moiety as an auxiliary donor were designed and synthesized for solid-state dye-sensitized solar cells. The sensitizer series was designed to develop a structure-property relationship. These dyes were obtained from the relatively cheap starting materials, without the use of expensive catalysts, rigorously anhydrous or oxygen-free conditions. The highest solid-state device conversion efficiency 3.9% (JSC = −7.9 mA cm−2, VOC = 760 mV) and fill factor 0.65 under 100 mWcm−2 (AM 1.5G) solar irradiation were achieved with the dye D3 containing a methoxy group attached to the triphenylamine donor unit employed between the hydrazone moiety and rhodanine acceptor of the sensitizer.