Syhthesis and investigation of photoelectrochemical properties of dye (n719)-zno thin films

A highly efficient ZnO photoanode consisting of three-dimensional (3D) nanofiber (NFs) for dye-sensitized solar cells (DSSCs) was synthesized by a onestep and seed-layer-free electrodeposition on a indium-tin-oxide (ITO) substrate at 75ºC in a solution containing Zn(NO3)2, KCl, NaCH3COO, and Na3C6H5O7. In this solution, KCl as the supporting electrolyte promotes reduction of NO3- and diffusion of Zn2+ and CH3COO- and C6H5O73- anions as the capping agents selectively inhibit the ZnO growth along the c-axis. The photoelectrochemical results revealed that the DSSC based on ZnO NFs has the highest power conversion efficiency (3.78%) in comparison with those of the DSSCs based on nanosheets (1.36%), nanorods (2.18%), and microplates (2.55%). It can be attributed to the large dye adsorption amount, efficient light scattering and direct electron transfer networks, hence leading to a significant improvement of solar cell performance. Therefore, the ZnO NFs structure can be considered as a promising and efficient photanode for DSSCs.