Indoline-dye immobilized ZnO nanoparticles for whopping 5.44% light conversion efficiency

Using indoline D102-dye, a whopping 5.44% light-to-electrical conversion efficiency owing to higher current density and open circuit voltage is explored for the ZnO nanoparticles (NPs)-based photoelectrode. The ZnO NPs/D102 dye structure has been designed onto indium-tin-oxide, electrons extractor, conducting and transparent substrate. The ZnO NPs of minimum [0 0 2] direction orientation compared to that of [1 0 0] and [1 0 1] directions, an indication of good charge transporting ability, with agglomerated grains of about 5–10 nm in diameters were immobilized in D102 dye for 1 h for dye loading. Low charge transport resistance and nearly 60% incident photon-to-current conversion efficiency were obtained. The results suggest that D102 dye can be potentially used for obtaining high performance ZnO-based dye-sensitized nanostructured solar cells.

► This presents a rare attempt to explore metal-free single carboxylic group photo-absorber in ZnO based DSSC. ► An exciting IPCE of 60% corresponding to 5.44% efficiency is a motivation to replace surface aggregating metal complex dyes in ZnO-based DSSCs. ► The mechanism of charge transport is meticulously explained using the electrochemical methods.